well on my gmod server ive had 5 admins, now 3, ive now learned who not to ever admin, though the 2 people i banned didnt do anything like crash the server they did things like give people godmode give them admin only weapons(which could crash the server) even make there own server was the last straw so i let them go,
general rules of thumb would be, know them for a while depending on how active/long your forums have been up would totally effect this, my server now has a 2week active minimum, and remember people should never have to ask to be an admin on forums or anywhere, they should just be regulars and act like they arent complete noobs and make sure they dont give any indications of being control freaks or anything that would potentially annoy other users, well its pretty easy to tell so just get to know them first then make your choises(also choosing your best friends just cause they asked can be a mistake)
Hallowed are the ori.