I like most of those ideas but I have to admit personally I am little sick of reboots in general,not just with Star Trek but everywhere. So I would rather see something set in the prime universe.
Riker on the Titan could work since that would tie into TNG and right now that series seems to be just as popular and have just as much Nostalgia for it as TOS and it would continuing the story instead of rebooting the universe yet again.