Saw it again today, had the same problems with it. Uninvolving story, a bunch of characters whose opinions and outlook never change (it also occurs to me, the audience has the same thing going on - we're never given a reason to see two sides to anything, it's very unilateral) and a bunch of vague stakes resulting in more questions than answers.
It is what it is, I know. Just sorta sad. I see this the way you guys saw Wild Wild West.
Me with WWW, ya'll with Avatar: "Hey, this movie's effects are awesome, and....I like it! Yeah, I think this works!"
Me with Avatar, ya'll with WWW: "The effects are good, but you're not imagining how good this could be if it was just...better."
Things that stood out to me this time include the score, which seems to either be mocking the plight of the characters or over-indulging it at every - single - turn, and Michelle Rodriguez literally painting war paint on her chopper when she attacks the fleet, completely making a target of herself in what would otherwise be a wise, stealthy situation. Also, Sigourney's Na'vi avatar has a human nose, not a Na'vi nose. That's why she looks weird.
The last thing I noticed is that a lot of the problems in the movie resemble the sort of problems you get in another situation - where an expansive book has been adapted to a movie, and certain shortening changes had to be made to make everything fit. The sidekick scientist guy's whole "I resent you for being Mr. Lead Na'vi, aaaaaand now I don't anymore!" two-minute episode, the backstory of Jake Sulley and his brother's actual qualifications, the state of Earth (and by extension, why unobtanium is important), the lack of compassion on the part of anyone but the specific Na'vi scientists and chopper lady.
There's also, wait for it, absolutely no externally redeeming quality to the Na'vi, as characters. They're total douchebags. They're in touch with nature, and the humans are apparently really, seriously evil, so that's how the movie plays out...but this goes back to what I was saying. Jake Sully is the only character with mostly-an-arc, and you could argue the pilot chick has kind of an arc as well (I wouldn't - she never seems like "one of them" in the movie, she's always compassionate), and the audience is in the same boat as the rest of the characters, with no multi-layered insight into the proceedings, a very confined sense from beginning to end of what's subjectively happening and how to feel.
In a stronger film, we'd decide to side with the Na'vi. (And that wouldn't be fucking hard to write, humans are literally destroying their home.) We'd witness someone on screen make some sort of a decision they weren't always going to make. We'd see why the humans decide to up and attack them, as opposed to keep trying peacefully - and sort of understand it.
We'd also see why the Na'vi are so important, aside from being innocent. We'd see a gentle one, or see one of them save the proverbial cat with a human. (Don't tell me Na'vi chick saving Jake's ass counts, she does it and then gives a completely unresolved explanation for why. "You have a strong heart?" So fucking what? Do weak-hearted things get to die? What do you even mean? You look fake sometimes, shut up.)
Anyway. Avatar. Be psyched for the Down in Front.
I have a tendency to fix your typos.