The movie isn't perfect. It could have done with a little bit more quiet time or bonding. Some reviewers say that the movie's constant action leaves one burned out by the end, and I can see their point. Only one of the new characters really grabbed me (Finn); the others I'm kind of meh on, though it's no fault of their actors (except for one, but he tried his best). They all did wonderfully.
Okay, enough. Now for details.
First: Harrison Ford must have loved this one to bits. He certainly put everything into it. This is Han Solo with depth- not so much wise, but definitely experienced. I really liked Finn, BB-8 was nothing like as annoying as I was afraid he would be, Rey and Poe and Maz were okay, and I can see where Kylo Ren was meant to be but didn't quite get there... but from the moment he pops up until he takes the Guardrails What Guardrails plunge, Han Solo is The Man in the movie. And I loved every single second of him on-screen. That's a tribute both to scriptwriter Kasdan and actor Ford... and I suppose Abrams gets a look-in too.
Now, then: on the questions:
(1) Is Rey a Mary Sue? For my part the answer is no. Rey is a survivor and a survivalist. In fact, I'm sure a lot of the people who are whining about Rey being a Mary Sue would claim her for their own... if she was a he. It's true she trips two of the criteria- she's universally liked or loved by the other good guys, and she's incredibly OP (that's overpowered for those who don't speak gamer)... but she misses on two other key criteria. First and foremost, she fits into the story and the universe- she's not obviously jammed in where there shouldn't be a place for her. Second, she's not perfect. She makes mistakes a couple of times- remember "the wrong fuses", for example? When adventure calls, she tries- repeatedly- to run away, even more so than Finn. She's NOT perfectly courageous or perfectly knowledgable or talented- remember the first moments flying the Falcon? If she hadn't been strongly Force-gifted, no way they survive her first flight! So no, Rey is not a Mary Sue- she's merely a classic hero, i. e. someone who can do things most people can't.
(2) Is Poe Dameron gay? First, I'm annoyed that anyone cares. And after watching the movie, I can't remember any point where we see any gesture of romance about Poe- nothing more than cameraderie of fellows-in-arms. Certainly there's nothing in the movie which requires him to be gay. The thing is, you might say, "If there's no plot reason for him to be gay, why make him gay?" My response: "If it doesn't affect the story, why NOT let him be gay? Why is it important to you that the character NOT be gay?" But apparently it's important to some people, because apparently even the slightest hint that an action hero in a movie might not be straight threatens them deeply. To the one such person I expect to read this, I say: cut it out. You're acting like an idiot.
(3) Why are all the New Order characters except the leader so young? There is actually a meme going around that the First Order is made up of Social Justice Warriors, and they want to control everyone and everything because they're all young whiny entitled emos. Um... NO. Wrong. Dumbasses. The reason everyone in the New Order is young is that they're all too young to remember what the Empire really was like. Thus they're easy prey for propaganda, indoctrination, and (as is as much as said with Finn) forced mental conditioning. These are the equivalent of real-life neo-Nazis, especially in Europe. And they're also like a major component of the American right wing- that part which demands law and order and prizes control over others and freedom only for themselves.
(4) Why does Kylo Ren fail? Sadly, I don't feel like the actor playing Kylo Ren aka Ben Solo/Organa/Skywalker/Whatever has the chops for what is definitely the most delicate and skill-demanding role in the story. Kylo Ren is a young man under intense pressure. He is the child of great heroes and an even greater villain, and he's trying to find an identity for himself in their shadows. He's torn between sides of the Force, torn between role models, and under intense pressure from the Supreme Leader and his parents' legacy alike. Above all, he's terrified of failure. This is a role that demands a master actor... and we didn't get that. We got someone who comes off as fifty percent emo, fifty percent creep, and a hundred percent poseur. He was the biggest disappointment in the movie for me... which, I suppose, is praising the movie with faint damns.
(5) What single thing did I like most about the movie? What I like is: the bad guys are COMPETENT. The New Order's stormtroopers can shoot straight, and their captains and specialists are badasses. (Even their janitors *coughFinncough*.) The breakable thing that makes the Jumbo Economy Size Death Star go kaboom is heavily shielded, armored, and guarded by ALL THE DAMN TIE FIGHTERS. And the New Order's intelligence network... WORKS. And most of all... when an officer tells the Dark Side Dude that something's gone awry, they DON'T GET KILLED INSTANTLY. The New Order is so much more respectable an enemy than the Empire, and that makes the Resistance's fight the more compelling.
So... after "Attack of the Clones" I had no desire to watch or read anything Star Wars related ever again. I went tonight because I wanted something to do for New Year's Eve, and almost everyone whose opinion I respect who saw the movie loved it. Now I'm eagerly looking forward to two years from now, because I have NO idea where the story is going to go from here... and I really, really want to find out.
That said, I do kind of wish I hadn't spent $25 to see it. (The popcorn and drink cost more than the ticket.)
And side note: I am NOT watching any more movies in 3D. My eyes still hurt, and the effect wasn't convincing to me. It was more like View-Master, with one flat layer atop another flat layer. Things in the foreground blurred to unrecognizable shapes when they moved quickly. If and when I rewatch the movie, it will be in blessed, blessed 2D, so I can see the crap I missed the first time round.