The question is just begged why you can't leave your FC, but if you feel that way, I have seen some people shouting for social LSs in Limsa from time to time. The most reason one before I had to take a work hiatus was Azure Sky. It was really active before I the break I had to take from FFXIV, but it seems to be quiet now. But with it being the holidays, everyone may just be with family. Maybe make your own and try getting friends to join if you'd like to get the ball rolling on what you're looking for.