Kirk saved the Earth and countless Federation worlds by stopping a ship from the future that no one seemed to be able to stop (I'm assuming that Nero destroyed a bunch of Vulcan and Federation defense ships offscreen, before facing off against the Enterprise...) - that's impressive.
It wasn't exactly single handedly though.
It was his plan to have Spock pilot the "Jellyfish" away from Earth ...
I must have missed that.
I agree with your point about his lack of maturity though. The way the writers handle that will at least be interesting.
All those technicalities, they're pretty much dead on arrival in a film of this nature, they are in fact useless weight and beside the point.
Well yes, I agree, it does seem that any attempt to make sense or behave decently (see below) in a contemporary ST movie is now sadly "beside the point", as you put it. Still, we live in hope.
No,Spock did not "save Earth as much as Kirk" he had to be manipulated into taking the right actions by Kirk who had the proper instincts do what had to be done.
I think its clear that Spock did as much or more than Kirk to save the Earth. Sure, Kirk warned everyone about what was happening at Vuclan but it was Spock who, despite being "emotionally compromised" kept this head when Kirk wanted to go charging off after Nero with not a plan in sight. There can be little question that following Pikes orders was the correct decision at the time. Pike new it would have been suicide to go up against the Narada at short range and long range wasn’t yet an option. Chekov later agrees with Kirk that they need to stay invisible to Nero or he would destroy them. So its ironic Spock made the right decision, hard thought it must have been to ignore his desire for revenge, while Kirk "demonstrated his command abilities" by throwing a completely unbelievable (if "fortuitous") hissy fit and got himself thrown off the ship.
Then, when Kirk "luckily" came across the technical information (transwarp beaming) they needed to give them a fighting chance against Nero, he didn't tell Spock what he had discovered and give him the option of changing his mind. Spock could well have done so, he was making better decisions than Kirk was and he later volunteered to help when he knew the score. Instead Kirk deliberately keeps his boss in the dark (way to be a team player) in order to steal his command. I think we can ignore the writers' attempted rationalisation here.
And Kirk still didn't have a plan! Finally he comes up with: "Whatever the case, we need to get on board Nero’s ship undetected". Brilliant! But how? It was left to the crew and Spock (miraculously recovered from his mental breakdown after a quick pep talk) to work that out. Kirk just tagged along on the mission so the writers could give him the credit. I think we just assumed that Kirk saved the day, but that’s only because we expected him to. While they both put their lives at risk, it was of course Spock’s actions, with the help of the Enterprise, that destroyed the Narada and saved the Earth.
By the way, did anyone notice that after Nero ordered his crew to fire everything they had at the Jellyfish, the Enterprise easily managed to destroy the entire salvo! If the Enterprise's point defence was that good, why were they worried about Nero and his ship in the first place!?
As for promotions, they could have made Kirk first office under Pike and have the next movie start, four years down the track, with Kirk congratulating Pike on being made an admiral … .