There was a lot going on in the movie. Too much for two hours. Maybe a two-hour tweny-minute movie wouldn't have been such a bad idea. Not to do more, but flesh out Nero's motives just a bit and add a tad more gravitas to Spock Prime's role. Perhaps the movie an overall connective theme. But as far as handling the characters goes, overall, they did a good job except for two things that bothered me from a fan's point of view.
1. The Spock-Uhura relationship. Where is this going? Can this be good? For this old Trek fan, it was awkward to watch. OK, this Spock is about eight years younger thant he one we meet in TOS. And, he's having emotional issues. But it's a direction I hope they veer away from in the next movie. Is Uhura going to be Spock's new confidant? Will they go deeper into the relationship? Will they break up in the next movie? How does any of that affect the dynamic of the overall character relationships. Will they become "just friends," or completely alienated? I just wonder if Abrams, Orci, and Kurtzman thought it through beyond this movie.
Part of Spock's mistique was that he was insular, alone, mysterious, isolated (no real friends on board other than Kirk and McCoy), and somewhat dark and even a bit brooding. Compare this Spock's relationship with Uhura to TOS Spock and how he wouldn't allow himself to pursue a relationship with a very willing Christine Chapel. We'll see where they take this relationship. Will this Spock need to open up to Kirk as much as the other Spock did? Will Uhura jump all over McCoy the next time he makes a smart remark at Spock's expense? Will she dislike McCoy for apparently disliking Spock?
2. I started an entire thread about the final destruction of Nero, and I won't rehash it here. Suffice it to say the simplest solution to what I believe was wrong with the scene would've been to have Kirk and Spock reverse their lines. The way it was didn't work for me at all. The other way would've been more acceptable and a bit more within each character.