Originally Posted by Kaboom
Overall, since he's stuck in this "alternate" timeline, to which the Temporal Prime Directive likely doesn't apply much to, he'd probably see fit to warn the Federation about a few of the "big" things that might threaten it or its present and future allies. Like V'Ger, the Whale Probe, the destruction of Praxis, the Borg, the freakin' Nexus, etc...
perhaps the next movie could be about him solving all these big things in one go? /sarcasm