They are all are spot on to the characters. Scarry so. Whatever the weaknesses people think Orci et al have in storytelling, they've been very true to the characters, and the actors have been, too.
Not even close. Spock would never have a relationship with his subordinate. He would have thought it inappropriate. And I really can't blame it on the actors because they did try. But it just wasn't written into the story for them to act like they were the original characters. I can see how this could affect Kirk as he had a father in the original and didn't for more than a few minutes in the nuTrek. But did the destruction of the Kelvin really affect that much? I can mostly chalk it up to it being a parallel universe as the reason that they are acting that much different. But as I said, a character like Scotty, the personality just wasn't there. It was all just his accent. Or maybe it was the apparent intelligence that wasn't there. Both Scotty and Spock stick out the most in that. They were supposed to be the smartest ones on the ship and then Chekov was doing his "Wesley Crusher with a Russian accent" imitation in the first movie.
So, if Jack Black....yes that Jack Black--as is--slipped on the pointed ears, delivered his lines in a monotone voice and sported the haircut, he would be Spock, just as much as Nimoy?
I wish they had a clapping Smilie just for this post.