Didn't read the whole thread. However I know what I hated about the movie, and it will go in order of most hated to least:
1. Killing of Kirk.
I don't care what anyone says or how they try to sugar coat it. The character of Kirk to most Star Trek fans is an icon and a legend. He is the main hero of Star Trek. You can't kill off a main hero in a story and leave him dead, unless the point of your story was to be a tragedy. I remember sitting down to watch the movie with my dad and my little bro (who was 15 at the time). When Kirk died, my little bro started crying, and my dad just looked at me like someone sucker punched him in the stomach (TOS being his favorite series). What the fluck is wrong with these writers?? Chimpanzees could have written a better story.
I know what they were trying to do. They were trying to heavy handedly say "TOS is dead guys, TNG is taking over the reigns".
Well it heavily backfired on them. Anyone that knows me knows I like TNG as my farorite series, and while I enjoy TOS, TNG is just a bit more fun for me. HOWEVER, NO CHARACTER in TNG can even hope to come close to the charisma of Kirk (and by proxy, Spock and McCoy). And of course, killing Kirk felt like they were killing the hero of the story, even if it was supposed to be TNG and not TOS (most regular trek fans do not frikkin' care about the difference).
Anyway, how would I have handled Kirk in this movie. Well, scratch the whole storyline and come up with something where both crews work together to solve a problem, and in the end, Kirk and crew say to Picard and crew: "Captain Picard, your crew truly is worthy of being in command of the Starship Enterprise" or some line like that.
Oh boy, like 90% of Trekkies would have an orgasm right then and there, and the casual viewer would have said "wow, that was pretty damn funky! this movie wasn't so bad"
But if they HAD to keep the same story, then don't kill the guy. Give him the highest honor on Earth by Star Fleet, let him retire peacefully, maybe even have him meet up with the Scotty from "Relics". See? it writes itself?
2. Destroying the Enterprise D. Huge mistake. The Enterprise D was such a huge part of TNG, that destroying it was destroying an iconic part of the series. How would TOS fans have felt if the Enterprise had been blown up and replaced by an Excelsior for all 6 movies? Well that's what the TNG movies did. To make things worse, they replaced it with this insect looking thing that has hideous Nacelles.
Those were the main movie killers to most people I think.
There's also more minor quibbles like:
3. The nexus. It doesn't make sense story wise. You can't fly up to it on a ship, it has to come to you. So how come Kirk got sent up to it on a ship? Soran should have just taken a shuttle by himself, stopped it right in the nexus' path, and let it come to him, end of story.
Oh but they couldn't use time travel because it's so cliche. Right, and they ended up going to Time Travel again for the 2nd TNG film, and it actually turned out to be pretty decent, go figure.
Of course, since being in the nexus means you can go anywhere in time, go back to the point Soran steals that trilithium stuff and catch him there, making the crew aware exactly of what's going on. No need to even get Kirk involved, leave the guy enjoy his nexus at least.
4. [Simpsons moment here] "Ah!! again with the Klingons!!"
TNG wore down the Klingon stories. Come up with something new dammit. Personally I think it was all done to reuse the footage of that exploding Klingon BoP, which was severely lame.
All in all, a horrible movie that makes me sick. Only Nemesis is worse.