1. I don't know if it is possible, but could one eliminate the entire cadets on a training voyage angle from Star Trek 2? I would think that by cutting out some key lines, it would be possible. Plus, it doesn't really add anything to the story.
2. Forget about ST: Generations. That movie was about the next generation, and not really about the original cast except for Kirk. I would think that any Generations edit would have to make it an episode of ST:TNG, not Star Trek Phase 2. At least don't let Kirk die for such a poor reason and in such a lousy way, if you are going to do it. I didn't think either death in Generations was fitting for him.
Good luck on this project!