The changes in Spock are the more interesting for me because he has always been my fav character. In TOS he was ashamed of his human origins ("Naked Time") and it took him decades to accept this heritage and live with it. NuSpock* isn't ashamed of his human side and it's obvious even as a kid. There's a "I love my human mother" factor that didn't seem to be enough in TOS for Prime Spock to be more acknowledging of his human side when he was young. You can see that again with the Vulcan council "fuck off" scene.
It becomes even more interesting when Sarek's attitude, which was previously close to Prime Sarek's, changes after Vulcan's destruction and Amanda's death. I would have never dreamed to hear him say to Spock that he's glad he's got him (widly paraphrasing here, bad memory and movie dubbed in French) and that he married Amanda because he loved her (that scene is wonderful). He even encourages Spock to use his emotions!
That is going to change Spock a great deal and it can already be seen in the transporter room with Uhura (it took me 3 viewings to understand and accept that scene).
actually to me both are grounded in tos.
while spock had yes issues dealing with his human half he also was very loyal to his mother even though he wasnt talking to his father like a father for a long time we do know spock had gone back home to see his mother.
and frankly the scene with young spock is pretty close to one we see in yesteryear..
were young spock dosnt respond to the taunts of the vulcan children until..
Your father brought shame to Vulcan. He married a human.
that is when young spock tried to attack them.
as for sarek .. well go and watch the end of journey to babel sometimes.
i wasnt suprised at all by sarek's admission after that.
really the casting of sarek was one of the few i think they miscast.