I’m admittedly not familiar with the NC public school system, but I do know a few things about choosing an LGBTQ-friendly school. My main advice would be to look at their websites. Even if they’re not on Campus Pride, they should say if they have either an LGBTQ office or, more generally, a diversity office. They also probably have a list, somewhere, of all the clubs and activities available on campus. Do they have some sort of Pride group? I know it’s summer now, but do they have past listings of things like drag shows, dances, rallies, etc.?
The presence of such groups and offices can be a good sign. What’s even better is if they list their contact information, as many of them hopefully will (the diversity offices/resource centers should have phone numbers or emails, even if the Pride student groups don’t). You can contact them to ask how active the groups are, how friendly the campus is as a whole, etc. They should be used to answering such queries from prospective students.
As for nightlife – do you mean in terms of the community? If so, Google is definitely your friend. Check to see if there are active bars and clubs, if there are community centers, etc. In general, the more urban a location is, the more you’ll probably find. If a school is in a more rural area, you might have to commute to find a good night scene.
I hope that helps. Sorry I don’t know anything more specific – have you checked to see if any of the schools have their own forums here?