I'd rather see the rise and fall of Garth of Izar before he was institutionalized. Or to really go off the wall, we learn tribbles are voracious carnivores.
I'd like to see absolutely nothing bad happen to Garth in this timeline. Perhaps all, or many, of those 'evil Captains' won't be evil this time around? Spock Prime could have helped warn them of what was to come.
I also hope they don't do the Borg in STXIII. I hope they come up with something new. Perhaps there could be a film without antagonists? Such as a natural disaster or other thing like that. A film without villains? I'd watch it.