Sulu's "Why, why it's Mr.—" from ST—TMP is even worse. No one talks like that.
We English speaking folks now don't talk in the way that English speaking people had 300 years ago?
I perceived the scene's idea that nobody was expecting Spock to ever return since he was off looking into Kolinahr* and *boop* there he is, much to everyone's shock...
* especially after ingesting too much plomeek pretzels and/or trying to purge emotions
I always took it that they chose to stay on Vulcan to keep an eye on Spock while Sarek tried to work some diplomatic channels on their behalf, probably offering diplomatic immunity to them so long as they were on Vulcan. Also, since the Klingon ship was foreign and had been damaged in the brief fight over Genesis, it makes sense that Scotty would want to go over it with a fine-toothed comb to make sure it wasn't going to fail in flight, and that the crew actually knew how to fly it properly. Plus, hey, gotta completely replace the bridge, right?
^^this
Movies 2-4 take some liberties with established traits and lore, but IV's takes the cake in Scotty re-rigging the entire Klingon ship's bridge to something Starfleety. On top of the supposed peace talks and Kirk trying to not kill Kruge every 3 seconds from the previous film, now the Klingons will simmer and shriek "SPIES! Tearing down equipment to see how it works?!"
Why he would disassemble bits of the bridge just to make it feel like the Enterprise... they just got this big piece of constructed alien technology and there's no manual anywhere, so to make drastic changes in... how much time had elapsed? ... seems a possible miracle work for sure. Then again, 300 years of evolution, humans would be smarter all around or so a theory goes. Or the technologies between species isn't all that different, some laws of physics do remain the same regardless. People still have individual traits as they all can't be captains and the engineers ensure everything works.
Plot holes are inevitable, but as with a cake, no single ingredient makes the cake better than the ingredients a la carte. I mean, raise your hand if you've sat in front of a cake, a cup of wheat, two eggs, glass of milk, pound of sugar, then took one bit of cake followed by gulping down all the other assorted ingredients and tell me you prefer the individual ones unmixed. Apart from body builders since some of them crack an egg in a glass and drink it raw... I wonder if their cholesterol levels are higher than a horse in heat in a hippie hut, but that's not important right now...