favourite bit of acting: the look on Scott’s face when he’s reassigned to Excelsior
he is clearly thinking ‘I have started barroom brawls with Klingons over far less, Admiral, do. not. take. my. Enterprise.’
roughly the same look as when the Excelsior captain brags about how they’re going to break Enterprise’s speed records
polite smile and grit teeth like ‘nope nope nope that is my wee bairn you’re talking about.’
really even if Kirk hadn’t essentially told the Admiral he intended to go back to Genesis, everyone should have seen Scotty going rogue on Excelsior coming.

also Uhura does not get nearly enough screen time in this film.

keelan has trekkie feels time

So all Trekkies already know the whole Vulcan logic thing is not natural, right? Naturally they are quite emotional, but also quite violent, and focusing on logic instead of emotion is literally their main defence against becoming rage-filled serial killers.
But, consistently, they will do incredibly illogical things to help their families. There’s even a book (The Vulcan Academy Murders, i think) which explicitly states family comes above logic for them.
Every single scene with Sarek in it makes this perfectly clear. Hell, he damn near gets in a proper argument with the Vulcan priestess – and as soon as he pulls the ‘this is my son’ card she lets him have his illogical way. Because she knows damn well you can’t go logical on a Vulcan whose family is on the line.

and then that last conversation Sarek has with Kirk when he mentions David
yeah i’m just gonna need to assume the writers of this one wanted to make this one especially sappy

BUT COMING UP NEXT IS STAR TREK IV: THE REALLY FUNNY ONE. so it all works out.