Among most pro-star wars apologetics, a common belief seems to be the unrealistic worldview that there is no perceivable way that star trek can win a war against star wars.   It doesn't matter if you're talking about sheer firepower from species 8472, intervention from Q, or even time travel.  In this case, I will be addressing the time travel arguments as presented at stardestroyer.net.  (All quoted material from stardestroyer.net will be in white font color.)

"Ah, time travel. As a good Trekkie might say, "our last, best hope." I'm sure you've heard this argument before:

    "The Federation would use time travel to jump into the past, and wipe out the Empire before it was ever created.""

Yes, this argument plus this one:  "The Federation would use time travel to jump into the future, grab as advanced technology as needed, then destroy the Empire in a direct assault" (a similar strategy used by Henry Starling in voyager episode "Future's End" to advance the human race)

In order to have logically coherent arguments, I will be using evidence from star trek episodes and movies to prove my points.  Afterall, as quoted from stardestroyer.net's own website:  "Canon is the body of admissible evidence for any particular universe. The age-old question of what is and what is not canon is one of the most salient points of the debate, and has perhaps surpassed the actual technical debates as the key issue in the whole Star Wars vs. Star Trek argument.".  This means that I'm not as interested in arguments regarding how plausible certain technology is or how logical they find it to be.  The assumption stands that if it happens in Star Trek then it can happen both scientifically and logically.  Regardless of your own personal belief, this is still proof directly from star trek canon sources and can be used to make arguments against a claim made by pro-star wars debaters.

Some of the problems of this essay's arguments comes from just the article itself being outdated.  The essay is said to be written on april 29th, 2000.  This means that his article does not consider canon evidence from all Star Trek Voyager episodes after the Voyager episode "Muse" from Season 6 and the entire Star Trek Enterprise series.  The episode right after Star Trek Voyager's episode "Muse" is the episode "Fury"  involving Kes, ironically, going back in time.  There is a total of 30 episodes from Star Trek Voyager, 98 episodes from Star Trek Enterprise, and 2 Star Trek movies that are not considered in this essay leaving behind over 17% of all star trek episodes and over 14% of all Star Trek movies.  The Star Trek Enterprise's main theme is also centered around time travel giving an abundance of evidence which rips to shreds the theories presented on this essay regarding time travel.

The author presents 3 questions to the readers: Why so rare? Can they pull it off? and What's the point?

Regarding the question of "Why so rare?":

"If time travel can be used as a panacea for every mistake, battlefield defeat, and ill turn of fortune, then why is it used so rarely on the show? Why were crushing defeats like Wolf 359 or the Romulan/Cardassian massacre in TDIC not reversed by time travellers? Federation law? Let's not be silly; if any ship with warp drive can use the slingshot, this opens up time travel to every half-assed starship captain in the galaxy."

As we can see, the Star Trek Enterprise and late Voyager episodes not considered in this essay.  Time travel is used commonly by many factions that try to compete for dominance.  It's not rational to dismiss the federation law argument so easily now, after the episodes we've seen since April of 2000.  They make it clear that the Federation in the future and present makes reference to a Temporal Prime Directive and Temporal Accord which prohibits contamination of the timeline.  The Temporal Integrity Commission is always monitoring for changes in the timeline and traveling back in time to minimize the effect of temporal incursions.  Evidence of  the Temporal Prime Directive, Temporal Agents, and Temporal Integrity Commission can be found in episodes such as "Future's End" Voyager, "Relativity" Voyager, "Shattered" Voyager, "Endgame" Voyager, "Cold Front" Enterprise, "Shockwave" Enterprise, "Carpenter Street" Enterprise, "Azati Prime" Enterprise, "Zero Hour" Enterprise, and "Storm Front" Enterprise.

Given this new evidence we can now say that Crushing defeats like Wolf 359 or the Romulan/Cardassian massacre are not reversed because it would contaminate the timeline.  Even if such efforts were made, the Temporal Integrity Commission should be able to detect this and stop interventions from happening.  It may seem like a good idea to intervene in these situations but it can have unintended repercussions such as not being able to learn from your mistakes or saving someone's life that turns out to be the next Hitler.

Regarding the question of "Can they pull it off?":

"We know starships can use the slingshot effect to travel several centuries into the past. However, this act requires fuel. It puts strain on the ship (serious strain, as we saw in ST4). So who's to say it could survive a much longer trip, say, a thousand years instead of a few hundred? What about ten thousand years? What about a hundred thousand?"

The federation are explorers above all else and as part of the exploration process they learn more about methods of time travel with each passing episode involving time travel.  The slingshot effect was used during the 23rd century in episodes "Tomorrow is Yesterday" TOS, "Assignment: Earth" TOS, and the movie Star Trek IV.  Surely if they can do this in the 23rd century, they can also do it in the 24th century especially with their advancements such as warp propulsion, power generation, and the invention of metaphasic shielding to protect them from the solar radiation.

Regarding the question of "What's the point?":

"In the universe of Star Trek, there are an infinite number of parallel timelines (as seen in "Parallels" and "Mirror, Mirror"). When a ship performs a time-jump, it must create a divergent timeline (more on this later). It can wreak havoc in this divergent timeline, but why would its departure have any effect on its original  timeline? "

The episode "Parallels" and "Mirror, Mirror" do have alternate universes.  These alternate universes were not created by time jumps though.  All evidence suggests that these alternate universes were there from the beginning just like the prime universe of star trek.  We can clearly see that going back in time can affect the original timeline because there are episodes that show it does.  Here are a few examples for now:

In episode "Yesterday's Enterprise" TNG we can see what looks like the original timeline changing because the Enterprise C comes to the future.  Tasha Yar and the Enterprise C are sent back in time and we then see what looks like the timeline restored to normal.  But in later episodes we see proof that sending Tasha Yar back in time with the Enterprise affected the original timeline because we get to see her daughter Sela in a later episode.

In the episode "Time's Arrow" we see that data going back in time alters the original timeline because we see data's head found in a cavern on Earth.  If time travel could not affect the current timeline we wouldn't see data's head like this.

In the episode "Past Tense" DS9 we see time travel to the year 2024 right before the "Bell Riots".  Benjamin Sisko has to pretend to be a hero in history named Gabriel Bell because the original Gabriel Bell was killed as a result of their interference with history.  After restoring the timeline and traveling back to the future we see in this episode and the DS9 episode "Little Green Men" that they have Benjamin Sisko's picture as Gabriel Bell's picture in historical records.  This shows that going back in time affected the timeline in which we see the regular star trek episodes later on.

We see from the Star Trek movie released in 2009 that going back in time can create an alternate universe.  I have no objection to this idea but I do have an objection to state that this always happens with every instance of time travel.  It seems more plausible that the effects on the original timeline depend on the method of time travel used.

Next he goes on to list various methods of time travel:
 

"It may be helpful to list known examples of Federation time travel, all of which fall into a small number of categories:

   1.Accidents
          *Too many to list. They usually involve some natural phenomenon, such as black holes, wormholes, or "temporal anomalies"." "

I would list in more detail other ways of time travel but this has already been done for me at http://memory-alpha.org/en/wiki/Time_travel_episodes

He dismisses accidents too easily.  It was time travel accidents that gave rise to his other categories such as slingshot effect, transporters, the nexus, and the bajoran orb of time.

   "2.Assistance by outside forces.
          *Guardian of Forever: Seen in "City on the Edge of Forever". Not large enough for a starship, with a lower range limit of at least a few millenia. It cycles through a list of "permissible" destinations, generated through some unknown algorithm. Doctor McCoy inadvertently used it to go back to the 20th century.
          *Borg Sphere: Seen in STFC. Capable of moving entire starships, with a lower range limit of roughly three centuries. It sent itself back to the early 21st century in an attempt to assimilate Earth's past, and the Enterprise rode its "temporal wake".
          *Bajoran Orb of Time: Seen in "Trials and Tribble-ations". Capable of moving entire starships, with a lower range limit of roughly one century. It was used to send the USS Defiant 105 years back in time, as part of a failed assassination attempt against Captain Kirk. The use of this device, as with all of the Bajoran orbs, is presumably contingent upon the forbearance of the so-called "Prophets".
          *Atoz's time portal: Seen in "All our Yesterdays". Not large enough for a starship, with a lower range limit of many millenia, perhaps even millions of years. It was used on Kirk, McCoy and Spock, who all suffered loss of reasoning faculties when moved to a prehistoric era.
          *Timeships: Specialized time travel vehicles from the future or from alien civilizations. Seen in "A Matter of Time", "Future's End", and "Year of Hell". The latter two examples are Voyager episodes in which the writers' abuse of time travel finally reached the "ludicrous" stage, making TNG seem downright reasonable by comparison."

The Guardian of Forever and Atoz's time portal may not be large enough for ships but it can be large enough to transport supplies including supplies needed to construct a ship in the past.  Possibly even using a transporter to beam larger supplies through the doorway that would normally be too large to physically fit through the doorway.  If Voyager was able to transport a test cylinder and the Romulan Telek through a micro-wormhole that went back into the past then using a transporter with the Guardian of Forever and Atoz's time portal should be possible too.

The bajorian orb of time was also used in the DS9 episode "Wrongs Darker Than Death or Night".  Just as a note that they do have a history of reusing time travel methods as they discover them.

As for time ships, in episode "Cold Front" Danials tells archer that anthropologists from 2769 traveled back in time to observe the building of the pyramids of Giza which would have been around 2560BC.  When Archer and Danials were watching the timeline resetting itself at the end of the Enterprise episode "Storm Front PT II" one of the first visuals we see are a picture of dinosaurs.  Which tells me they are capable of observing events as far back as 65 to 230 million years ago, between the Triassic and Cretaceous periods.  Which would be far enough back to time travel before any strong star wars empires existed.  They also show a picture of a single cell dividing in the background.  If this represents early cellular life on earth then that could mean they are able of traveling back even billions of years.

In the voyager episode "Death Wish" the Q transported voyager back to the birth of the universe believed to be some 14 billion years ago.
 

   "3.      Slingshot effect.
          *The slingshot effect uses some horribly unrealistic pseudoscience to explain how one might use the Sun to travel backwards in time. It was used to send the Enterprise forward from the 20th century to the 23rd century in "Tomorrow is Yesterday."
          *A slingshot effect was used to send the Enterprise back to the 20th century in "Assignment Earth".
          *A slingshot effect was used to send a Bird of Prey back to the 20th century in ST4."

I addressed this point earlier as a plausible method of time travel given advancements in technology in the 24th century.

   "4. Transporters.
          *First seen in "Mirror, Mirror." A transporter accident (how many of these have we seen in Trek?) threw Captain Kirk into an alternate timeline. This timeline was visited again in the DS9 episodes "Crossover", "Through the Looking Glass", and "Shattered Mirror", again using the transporter.
          *Transporters were also used for time travel in "Time's Arrow", "Past Tense", and probably several other episodes, always to travel just a few centuries back in time.
"

I said already that I don't consider "Mirror, Mirror" time travel since they are in the present each time they go to the universe.  It's just an alternate universe.  There was also a time portal found on Bajor in episode "Time's Orphan" DS9 where a transporter was used to transport Molly from the 21st century to the 24th century through the portal.

As we can see, most Trek time travel has been limited to a few centuries of "temporal displacement". The small handful of long-range time travel incidents have involved technologies which can only move a person, not an entire ship (thus suggesting that movement through time is similar to movement through space; the bigger the object, the more difficult the move).

Actually in the Enterprise episode "Zero Hour" we see Danials moved Enterprise back in time to the World War II era.

Time ships like the U.S.S. relativity are able to transport back in time under their own power.  A confrontation with star wars does not have to necessarily be from the 24th century.  It can just as easily be from the 31st century or later.  I would even consider this more fair since the technology in star wars has had thousands of centuries to develop into where we see it in the movies.   Humans have only been warp capable on star trek for a little over 300 years.  If star wars fans can use technology that has been developing for thousands of centuries years in then star trek can be allowed to use technology that has been developing for only hundreds of years at the very least.

The wormhole aliens in DS9 episode "Accession"  were able to transport Akorem Laan and his lightship two hundred years in the future.  We know the wormhole aliens are extremely powerful from being able to destroy an entire dominion fleet.  According to DS9 episode "Destiny", the origin of the bajoran prophecies is believed to be from the wormhole aliens communicating with Trakor 3,000 years ago giving him knowledge of things to come.  I see no time travel limits to the wormhole aliens since they exist outside of linear time.

And of course, the Q have demonstrated abilities to go to any time they wished.

"When we look through the list, we find that once we eliminate small-scale techniques and outside intervention, the only viable method of Federation time travel is the slingshot effect. This creates serious constraints. The slingshot effect places great strain on a starship, and long-range use of this technique has never been observed (or even attempted). The process consumes fuel at an undetermined rate. It places an undetermined stress on the ship. Given these problems, how can the Trekkies insist that there are no limits to the duration of time travel using the slingshot? How long must we suffer Trekkies who insist on assuming that every process is limitless and free unless proven otherwise?"

As explained earlier, if they can travel in the past with the slingshot effect in the 23rd century then it should be even easier to do it in the 24th century with advancements in technology.

There's no reason to eliminate outside intervention if it's a possible method.  If it's theoretically possible to get outside intervention in a verses scenario then it needs to be considered also.

-A faction in the temporal cold war could assist the federation in time travel
-the federation could acquire this technology from the future
-they could just use the time ships from the 31st century
-Borg time travel technology
-Krenim technology to erase the empire
-use the Guardian of Forever, Atoz's time portal, bajorian time portal, or a wormhole into the past combined with transporter technology to transport supplies needed to build vessels in the past.
-the wormhole aliens could send them to the past
-Q is capable of sending them into the past
-they could use the method that quark used to go back in time in the episode "Little Green Men"
-they could use the orb of time
-they can use the nexus

Plus many more and only one of these methods needs to work for the time travel scenarios to be taken seriously.

"In any case, even if they can somehow resolve the "how" part of the question, we must still wrestle with the "why" part of the question. It is widely assumed that problems can be "solved" through time travel, ie- if something went wrong, you can go back and make it "right". But does this make sense? How does time travel affect the timeline? This question affects the potential usefulness of time travel as a solution for problems, and it leads directly to the infamous "grandfather paradox." "

It is widely assumed that problems can be "solved" through time travel because we see it happen in numerous episodes.  Many of which came out after this essay was written.  It doesn't have to make sense to you to be true.  If we see it in the episode then we know it can be done as per star trek canon evidence.  We even see episodes which specifically address the grandfather paradox.

He now goes on to talk about the Grandfather Paradox and his "many worlds" interpretation that is supposed to explain every single time travel event on Star Trek.

"We've all heard about the Grandfather Paradox. You step into your handy-dandy time machine. You jump back in time. You murder your grandfather. Now he's dead, and he won't ever sire your father, who in turn won't sire you. This means that you won't be born. But if you were never born, then how could you go back in time and kill your grandfather?

This is an old question, pondered by scientists, philosophers, and anybody who watched "Back to the Future" or "The Terminator". One obvious solution is that time travel might simply be impossible, thus eliminating the problem. However, general relativity predicts the existence of wormholes, and wormholes would theoretically permit time travel. Stephen Hawking has suggested a sort of "cosmic censor" who acts as a universal timecop and ensures that causality paradoxes never happen. This timecop might kill you before you can kill your grandfather, or make him duck to tie his showlaces just as you pull the trigger, etc. And of course, those who optimistically predict the eventual feasibility of time travel tend to resort to the "many worlds" interpretation of quantum mechanics.

Now, I must preface this with the very important caveat that the "many worlds" interpretation of quantum mechanics has been widely discredited. However, if we are using suspension of disbelief, then we must assume that it is valid anyway, because the parallel universes predicted by the "many worlds" theory have actually been observed in Star Trek. Parallel universes were seen first in "Mirror, Mirror" and then more spectacularly in "Parallels", where hundreds of thousands of Enterprise-D's from parallel universes could be seen.

Now, how does the "many worlds" theory explain the Grandfather Paradox? Well, if an infinite number of parallel timelines exist, then the Grandfather Paradox can be explained quite easily. You step into your handy-dandy time machine. You jump back in time, but in the process, you create (or enter) a divergent timeline. You murder your grandfather, but this happens in the new timeline. Back in your original timeline, your grandfather was never murdered, so you still exist. In effect, you are an alien visitor to this new timeline, having come from a different universe."

On the surface we see the grandfather paradox violated all the time.  Obrist in episode "Year of Hell" says his parents were erased and never have existed yet you see that he still exists.  The "single world" theory that I use to counter his "many worlds" theory is that Star Trek has technology which can shield them from changes in the timeline such as:

-the temporal shielding used in the voyager episode "Year of Hell"
-the temporal wake used to protect the Enterprise-E from changes in the timeline in the movie Star Trek First Contact
-being in close proximity to the Guardian of forever stopped the landing party from being erased while the rest of the federation was erased
-when the federation disappeared in DS9 episode "Past Tense", Kira asked why they weren't affected and O'Brien theorized that the singularity that polarized the chroniton particles created some kind of subspace bubble around the ship the protected them from changes in the timeline
-Guinan had a natural ability to sense there was something wrong with their timeline in episode "Yesterday's Enterprise" showing she had a natural ability to be partly protected from the changes in the timeline
-The U.S.S Relativity also had technology that protected them from changes in the timeline.

Not only does my theory explain all of these situations but it is supported by more Star Trek canon evidence from both visual and dialog plus it addresses problems that his "many worlds" theory does not.

According to him, when you go back in time you really enter another another universe and not your own timeline.  The reason everything looks normal again upon your return is because you did not change history in that timeline.  Here are a list of problems which his theory would have a hard time explaining:

-in DS9 episode "Time's Orphan" why did Molly disappear after telling her past self to go back through the portal which would prevent her younger self  from being stranded on Bajor?  If they pulled the older Molly from an alternate universe and then sent her back in time to her younger self in another alternate universe then sending her younger self back home shouldn't have made her disappear like that.

-why did the whole federation disappear in episodes TOS "The City on the Edge of Forever", DS9 "Past Tense", and Star Trek First Contact?  In each case we see some time travel but the ones that did not travel back in time yet experienced the federation disappearing without going back in time themselves.

-why do the visuals show the 24th century changing when the Enterprise-C came to the 24th century?  Also when the Enterprise-C goes back in time everything looks the way it did before except now we see Tasha Yar's daughter in the timeline

-why is data's head found on earth in episode "time's arrow"?  Even if you try to prove this head is from a data in an alternate universe, it still proves that it's possible for someone to change their own history.  Furthermore, how was Picard able to send a message to the future by putting a binary message into data's static memory using iron filings if the future is an alternate universe?

-In voyager episode "Year of Hell", how could the krenim temporal weapon erase things from history (including itself) if it's not possible to change history?  Even if you try to argue that they enter alternate universe's, why does voyager appear to follow them while they have their temporal shields up?  And why does the temporal shock wave appear to move through a single universe.

-In DS9 episode "Children of Time" why do the crew's descendants disappear after the defiant avoids the accident which throws them back in time?  Surely if their ancestors are from an alternate universe they shouldn't be affected by this.

-In DS9 episode "The Sound of Her Voice", are we now expected to believe that they were communicating with a woman in the past from an alternate universe that just happens to be at the same coordinates of where they find her dead body?

-In DS9 episode's "Little Green Men" and "Past Tense, Part II" why is Sisko's picture in the historical record for Gabriel Bell if they cannot alter the past?

- In voyager episode "Time and Again", how can voyager's future actions cause a disaster on a planet if it's not possible to change history?  Also why do they show the visuals of everything disappearing after voyager stops the rescue attempt that destroys all life on the planet?  If they are from an alternate universe then they shouldn't be disappearing like this.

-How can temporal agents police the timeline (like we see in Enterpirse episode "Cold Front") if it's not possible to go into the past in their own timeline to stop them?

-In the Enterprise episode "Storm Front", why does Vosk tell a Nazi that he can erase him from history as if he never existed when according to your theory he can't?

I'm sure I can come up with questions like this all day long.  With enough imagination, disregard of visual effects and dialog, amazing coincidences from parallel universes it may be possible to explain these things away but the explanations will be more complex than the alternatives.

"This solution is not without problems. If you move from one universe to another, then mass/energy conservation laws will be violated because both universes will experience a mass/energy change. However, this can be solved if an equal amount of mass/energy goes the other way, to take your place. Interestingly enough, this is precisely what happened in "Mirror, Mirror". Kirk and his mirror-universe alter ego changed places, thus preserving symmetry. This symmetry is not seen in the TNG and DS9 time travel incidents, but that's merely another example of how TOS is superior to its bastard stepchildren. One could always rationalize it by saying that the return mass/energy was dispersed widely across space etc., but the symmetry shown in "Mirror, Mirror" is a better solution. "

If your solution is without problems then maybe it's wrong.  This could pose a problem for a "single world" theory as well.  Here's how I handle it.  Either the mass/energy conservation laws make time travel impossible or they don't.  If mass/energy conservation laws do make time travel impossible then we know that mass/energy conservation laws cannot always hold true since we can see that time travel does occur on star trek.  Conversely, if the mass/energy conservation laws don't make time travel impossible then this just isn't an issue to worry about.

Additionally, we see time travel in star wars as well.  For example in canon story "tilotny throws a shape", storm troopers are sent 8,000 years back in time.  Princess Leia sees them as decayed corpses in the present.  There is little point in questioning the logic and scientific plausibility of time travel if Star Wars has the same flaws.  

Now he tries to show how his theory is supposed to solve problems that "single world" theory does not:

""City on the Edge of Forever": When Doctor McCoy jumped through the time portal, the other crewmembers on the planet's surface perceived the sudden disappearance of the entire Federation. Supposedly, he changed the past so that the Federation was never created. But that is impossible because the other crewmen still existed. They still had memories of the Federation. They still had Federation uniforms and Federation weapons. The "many worlds" theory neatly explains this problem: McCoy and all of the people on the planet's surface were all transported into a timeline (or parallel universe, whichever you prefer) in which the Federation never existed. The original timeline is not destroyed, thus explaining why they still remember its history, but they can no longer perceive it or return to it. When Kirk and Spock jumped back to "fix the damage", they caused everyone to jump into another timeline, in which the Federation was founded again, but with slightly different events surrounding Edith Keeler's death. This is not the same as "going home", but as far as they're concerned, it's good enough. "

First off it is not impossible that they can retain their memories with "single world" theory.  According to "single world" theory, everyone on the planet was protected from changes in the timeline probably as a result of temporal technology built into Guardian of Forever.  This makes perfect sense when you consider that whoever built the Guardian of Forever probably knew it had the capability of erasing itself so they would want to build it with technology to prevent this from happening.  He says that everyone on the planet gets teleported to an alternate universe with Kirk, Spoke, and Mccoy  but does not say how they get teleported to the alternate universe.  Why don't they just disappear like the rest of the federation?  He claims it's impossible for the crew to be in the same universe and then replaces this problem with another unexplained problem of how they got transported to the alternate universe.

""Star Trek First Contact": When the Borg jumped into the past, the crew of the Enterprise perceived the disappearance of the Federation's entire history. This is impossible because they still exist, and they still retain all of their memories, equipment, history files, etc. Data suggests that they were somehow "shielded from the changes in the timeline", but he doesn't even attempt an explanation of how this is possible. The "many worlds" theory provided a neater explanation: they were dragged into a new timeline by the Borg sphere's "temporal wake", and when they stayed in the wake long enough to perform a similar jump, they ended up in yet another timeline. In this new timeline, they tried to "fix" events so that they unfolded more or less as they remembered (albeit with an orbital bombardment of Cochrane's launch facility which didn't occur in their original history). Note that the "many worlds" theory also explains the biggest conundrum of STFC: why the Borg fought their way to Earth before performing the time-jump, instead of making the jump from the safety of their own territory. The answer is that a time-jump would move the travellers to a divergent timeline but it would have no effect on the original timeline. Therefore, it would do the Collective no good. You might ask why they performed the jump at all if this is the case, but the Queen's attack had failed and she was facing imminent destruction. A jump into a divergent timeline would not change history in her original timeline, but she may have found the prospect preferable to simply being destroyed by one of Picard's quantum torpedoes."

Data doesn't say somehow they were protected from changes in the timeline.  He says that the temporal wake must have protected them from changes in the timeline.  So you don't accept Data's explanation that "some how" the temporal wake protected them from changes in the timeline.  Instead, you ignore the dialog and say that "some how" the Enterprise-E is dragged into an alternate universe by the temporal wake.  All I'm seeing here is you trading one unknown for another while ignoring dialog in the process.  Why is the Enterprise-E dragged into the alternate universe before it even goes back in time?  How do we know that the orbital bombardment of Cochrane's launch didn't occur in their original timeline?  According to 7 of 9 in episode "relativity" it was destined to happen as a result of a causality paradox.  We know from enterprise episode "regeneration" that cochrane mentions this event at a commencement address at Prinston but then later takes it all back.  This gives a clue that he was hiding the orbital bombardment from historians and would explain why you think it doesn't happen in the original timeline but it really does.

You also used this to explain why the Borg Queen launched the time ship next to earth instead of in Borg space.  You say it's because the Borg Queen knows your theory is correct.   If that's true then how do you explain the Borg Queen on voyager explaining to Janeway that if she destroys voyager then she will never exist and nothing she will have done there will happen?  This concept would seem to contradict your idea that the Borg know your theory is correct.  Why bother to try to destroy voyager at all if they know your theory is correct?  The only explanation you can really give is that the Borg Queen didn't want to give Janeway the satisfaction that she won so she lied to her in order to confuse her even though they were both seconds away from death.  I understand that this episode didn't air yet at the time you wrote this essay so I'll let you off the hook for not seeing that.

The Borg would have preferred to be victorious in the battle and they probably would have been if Picard hadn't used his knowledge of the Borg to destroy them.   The Borg went back in time because their direct assault on earth failed and they wanted to assimilate Earth another way plus they wanted to save the Borg Queen.  It makes more sense that they would go back in time for 2 reasons rather than just 1.

""Yesterday's Enterprise": History seems to change when the Enterprise-C appears two decades away from where it was supposed to be destroyed in battle. But the original timeline is not gone, and in the new timeline, Guinan can actually perceive that the Enterprise-C belongs to a timeline other than her own (she can even perceive some of the history of that timeline). This perception manifests itself as a disquieting sensation that something is "wrong", but that's an oversimplification. After all, how can a timeline be "wrong?" With countless timelines in existence as seen in "Parallels", why would one be more "right" or "wrong" than another? A better explanation is that Guinan perceived enough of the Enterprise-C's original timeline to know that she thought it was better than the one she was currently in. We jumped to a divergent timeline when the Enterprise-C arrived and we jumped to another  divergent timeline when it departed.

Although the "many worlds" theory may have been discredited in real life, it seems to be the only way to explain Star Trek time travel as we've seen it on the show. It explains causality paradoxes in "City on the Edge of Forever" and STFC, and it also explains why time travel is not being used to solve problems, because it means that time travel doesn't really change anything. It only moves the traveller into an alternate universe where events unfold more to his liking. An interesting consequence of this explanation is that we've really been following a group of characters as they move from timeline to timeline, so we haven't stayed in a single universe throughout the series run of Star Trek. "

History does seem to change when the Enterprise-C appears.  You would need to ignore the visuals of this effect in order for your theory to still be true.  Guinan tells Picard that things are not right and Tasha is supposed to be dead.  You have to ignore Guinan's literal dialog and try to find deeper meaning in it for your theory to be true.  You asked how can a timeline be wrong if there are infinite timeline's in episode "Parallels".  In episode "Parallels" we see many quantum realities which are alternate universes.  Alternate universe's are separate universes with their own timelines.  An alternate timeline happens when the current timeline in their universe is changed.  It's more "right" or "wrong" than another timeline because history was contaminated from the future and this event was not supposed to happen.  Then at the end of the episode Guinan realizes that everything in their timeline is back to normal.  You claim that your theory makes everything simpler but I think it's far more complicated trying to figure out how all these infinite universes are interacting with each other every time there's a case of time travel.

Also your theory kind of hurts your side in a way if you think that they are constantly moving into parallel universes.  That would make it kind of difficult for Star Wars to do anything about Star Trek.

Now onto his conclusions

"Conclusion

We can now answer the original three questions posed at the top of this section:

   1.  Why so rare? This question can be answered by concluding that it probably is not so rare; it simply isn't perceived. There are probably countless time travellers, but each time a traveller leaves, he simply moves to a divergent timeline and disappears from his original timeline. Since we don't follow any timeline jumpers but the main characters, we don't perceive their activities. At best, we might perceive unexplained disappearances of starships, or mysterious "transporter accidents". "

In fact time travel is not rare at all as you would have seen in the Enterprise series.  It doesn't explain why the Temporal Integrity Commission is able to monitor changes in their timeline and how they are able to travel back and stop them.  If the factions are located in an alternate universe then how are they able to go back in time and locate them?  Wouldn't going back in time send them to another universe different from the one where they detected the factions?  Why should they even have a Temporal Accord or a Temporal Prime directive if they are not able to alter their history?  I think your theory would imply that they are unaware that they move to alternate universes instead of alternate timelines in their own universe.  How would you explain the visuals we see toward the end of the enterprise episode "Storm Front Pt II" where we see the timeline being "restored".  I'd say your theory would involve ignoring these visuals and dialog as well.

 "Can they pull it off?  That's an open question. We know that the only viable method is the slingshot, and we have evidence that there may be range and durability issues. However, the evidence allows us to establish lower limits but not upper limits. This remains an open question."

You're right that you established the highest lower limits shown but not the upper limits of your time travel methods.  You have no proof that these time travel methods aren't capable of taking them as far back as they please.  I don't really consider it an open question of whether there are ways to go back in time a sufficiently long enough time to get rid of the star wars galaxy with little resistance.  The only open question is whether they are able to get their hands on this technology again in the 24th century.  Or if you want to use the 31st century federation against the empire then there's little question that they can pull it off.

"What's the point? This is the real problem. The "many worlds" solution to the causality paradox leads us to conclude that a time traveller cannot change his original timeline. He can only move to a different timeline, in which events unfold more to his liking. For a soldier losing a war, it would be an act of cowardice since he would quite literally be running away from his defeat. That explains why they only use it when they've been moved to a different timeline against their will or by accident, since they can't get home but they can at least get to a timeline which they find preferable."

There are plenty of episodes that make it pretty clear that they are not in an alternate universe.  Your conclusions actually make the situation more complex and difficult to comprehend.  Whenever someone comes from the future they are really a guest from a parallel universe and when they go to the past they are really the guest of some other parallel universe and it's impossible to go to the future or past timeline of your own universe.  I find that it explains none of the problems that you say exists in the "single world" theory, it creates more logical problems than it gets rid of, it ignores visuals evidence, and it ignores dialog evidence.  It looks like you have used this theory only as an excuse to pretend that time travel cannot be used against the empire in their own timeline.    I'll agree that time travel can cause alternate universes such as the one in the 2009 Star Trek movie but not that it always does this.  Each time travel case should be handled on a case by case basis as to whether it takes them to an alternate timeline in their universe or an alternate timeline in a parallel universe.

"This appears to be a very long-winded answer to a simple argument. But the original argument is only simple because it deliberately overlooks numerous complexities affecting Trek time travel. When we take a more serious look at it, the time travel argument doesn't work."

Your answer isn't long-winded enough to the simple argument since it overlooks plenty of complexities of it's own.  If you take an even more serious look at it, the time travel argument does work afterall.