If he'd known earlier, he probably wouldn't have given Marcus the finger and tried to run to Earth. He WAS all set to summarily execute him until Spock appealed to his better nature and the obvious fact that shooting at the Klingon homeworld is probably a bad idea no matter how good your reasons. Knowing who Khan really is -- with all the gory details that entails -- would have put him back in a more or less killing mood.
I was talking about the specific moment after Spock finds out about Khan from Old Spock, not earlier. Would Kirk do anything differently had he found out right there?
Yes:
his phaser wouldn't have been set for stun.
It's not very Starfleet to kill someone in cold blood. They ended up freezing him in the end too, rather than killing him after extracting the blood "just to be sure".
It's not his trustworthiness at issue here. The trope in question is the "enemy of my enemy" face turn that often occurs in superhero movies: bad guy becomes a sort-of-good guy to take down a greater evil. In Khan's case, he was going for the "We're not so different after all" redemption schtick and doing a reasonably good job of selling it. Kirk didn't buy it, but it wasn't entirely meant for Kirk anyway.
It's a trope I really don't care for. If audiences suddenly feel "saw-wy" for Khan because he tears up a bit, that's their problem.
Note that Kirk Prime actually DID give Khan a second chance and the redemption narrative is the original ending of Space Seed. It wasn't until Wrath of Khan that we found out firsthand what a dangerous lunatic he really was.
A big mistake on Kirk's part, one that would come back to haunt him. I didn't like his decision to let them live on a planet, but I liked the repercussions and how it added much to his own personal crisis.
I lump this together with all the people on these boards who were angry that Chris Pine never did a Shatner impression.
To which I can only reply:
Way to lump me in with the rabid fans who can't tell the difference between writing and acting performances. I'm not asking for consistency in performances, I'm asking for consistency in character. I think Chris Pine is actually perfect for Kirk and has the right sensibilities and swagger for the role. However, the way he is written feels totally at odds with what I expect from Kirk but I don't blame it at all on Pine, because he's just working with what he's given. When Pine is given a moment that is reminiscent of the Kirk played by Shatner, he's VERY good at it and he never resorts to mimicking, he makes Kirk his own, much like how the Bond actors make the character their own while keeping the core intact. I point to the moment where Spock praises him for making the right decision not to kill Khan. I understand this is supposed to be a different Kirk, a Kirk without a father, but I really do not care for that interpretation because I want to see the heroic Kirk we're all familiar with but on new adventures. The ending implies that he "grew up" of sorts and gained a new respect for the chair, hopefully that will be reflective in the next film where they're on their five year mission. No more Frat Boy Kirk.
Then there's Khan. Given this is supposed to be the same exact guy with the same background, I expect him to be aligned with the Khan we saw previously, character-wise. Cumberbatch doesn't have to mimic the performance of his predecessor, but the writers should at least do a better job of making sure the writing is consistent. If they totally wanted to remake the character of Khan, it should have just remained John Harrison.
Why? The movie makes explicit references to the game AND the comics. The "holes" were were WRITTEN INTO THE MOVIE specifically to give those supplemental materials something to fill:
The Wormhole summed it best for me.
You don't. You're meant to ASSUME something is the case because the story wouldn't unfold that way otherwise.
I mean, unless you think "the Mudd incident" Sulu mentions is something from the previous film (or a reference to the Nibiru scene), you're meant to assume it's something that happened on a previous mission, before the movie started. That mission is a reference to the IDW comic series, just like McCoy's "I once performed C-section on a Gorn" refers to the video game, which -- in turn -- makes mention of the Nibiru Mission in Kirk's final log entry.
Basically, it's like Iron Man 3 referring to something that happened in The Avengers.
You see, I'm actually fine with the references you mentioned right there, because they're not vital. Just little easter eggs for fun, not something the film really depended on. It also gives the Enterprise a sense of history to those who never actually read those comics. I actually thought the Mudd incident was referring to Harry Mudd, as in they have already encountered him by this point. I still consider the thing with the crew being totally casual to the conversation minor, but I detest the idea that you have to read a comic book tie on or a video game tie in just to understand why there are holes the film left open. It's not everyone's duty to read a bunch of expanded universe books to get why the STAR WARS prequels are rife of plot holes and inconsistencies. The films should have never had them in the first place and no film should ever assume everyone is going to follow through the story because they went through all the tin-in material.
However, it is very different from references in IRON MAN 3, because at least those are expected to be picked up because it's safe to assume a major chunk of your audience has seen THE AVENGERS, which was a major film, not a comic book or video game. Far more likely than audiences knowing that the Trek comics are being brought up. If Kirk went through a very traumatic experience in a comic book and then the next film picked up on that with him having nightmares about it, I expect the film to explain why he's having those nightmares, not be asked to read the comic book. For me, the only canon that truly matters is the films. Comics, video games don't mean shit. That's how it is, not just for me, but for audiences in general.