Zod really wouldn't listen there, his mind is set to taking over Earth. You also have to remember in the beginning before he sent Kal-El to Earth, Jor-El said Earth is the best planet for Kryptoians and Zod knew that. Zod wasn't going to leave because Earth was their best chance at repopulating his race. Zod is stubborn and a villain, why is it out of bounds of imagination that he will be stubborn and not listen? He is a typical villain that you just know he isn't going to listen no matter what and feels he is above all creatures.
Again that discussion was the writer saying "Zod never said he'd destroy Earth" but he was wrong, Zod did say he would. Dude was looking for a mistake in the film but that mistake he pointed out wasn't there. Having Kal offer up the codex in his body so that Zod would leave is just changing everything, not pointing out a mistake that the writers/director made.
Yes he did have a choice. Saying he had no idea how to stop him is a cop out. Just like you 75 years of Superman comics to point to him ******* up, there's 75 years worth of comics of him stopping strong ppl without killing them (including Zod). I mean the same time he snaps his neck he could've simply directed it in to the ground or away from ppl or blow some ice breath on his head or his use on his heat vision to stop Zod's or to distract Zod break his arm so that momentary pain would cause him to stop his heat vision or instead of holding on to Zod use his super speed to save the targeted humans or a plethora of other outs.
Well now you're just changing the story they want to tell. Even if he temporarily stops Zod from killing that family, Zod will just keep on trucking and just cannot be stopped. At the end, the film is set up so that Supes has no choice and had to kill and that was the right time and had the biggest impact.
I mean sure the whole scene wasn't perfect, I mean why couldn't Zod look at the family and kill them with the heat vision? Why is it locked in to his head position/movement?
But really stopping Zod there is just delaying the inevitable. People were already complaining about destruction, if Supes just delays Zods death it'll just cause more destruction as the battle becomes extended but at the end of the day that is the message they decided to tell, that pushed to the corner Supes will kill as a last resort and that is to save humanity (which is shown in the comics). Again, he chose humans over his race. I also wrote all the times dude tried to save people throughout the film. I am not sure how much more care for humanity they have to show? It's not his fault another super powered being who cannot beat is throwing him around the city. He said it himself, kill him or he will kill all the humans.
Frost breath wasn't on the film by the way.
As for the comics reference, my reference of him messing up is to show it isn't out of character to the film because dude keep saying that they got nothing right. Using the history as an example of how to stop him isn't exactly accurate because those times has Supes either prepared with resources or are just more knowledgeable/experienced. In the comics he usually gets beaten, finds a way to stop or weaken his opponent and then come back stronger and win. The movie doesn't grant him that, he had to act on the spot and I cannot stress it enough but he is a newb at it. Sure they can change it but again that will take away to the message they wanted to send, to kill as a last resort. It wasn't his first choice, probably not the second or third or fourth and he completely mad at what he has done in the end.
Again how is he going to contain Zod there even if he doesn't snap his neck in the end? Zod has infinite stamina like him, better trained and skilled in fighting, determined to just kill, etc... No phantom zone, no ship or the help of his virtual dad and again he is a newb. The movie created that situation so that his action makes sense. Again I am sure you can find ways to stop him but the end result has to be Superman killing Zod (because that's what they wanted to show, it's not like they were writing it and they got stuck on that part and said, "what do we do now? Do we have to kill Zod?") and within the events in the film without changing it. Within the movies parameters and set up, what could he have done? That was the issue I am discussing about.
Now the decision to kill or not to kill Zod is a different story and people will just have to like it or not, agree and disagree because that will completely change the story they want to tell.