You can leave Gridania for Ul'dah or vice-versa before level 15, but you can't leave/go to Limsa before that (the event that gives you the airship pass is also the event that triggers ferries to and from Limsa to unlock).
You can't do 'main' quests (the ones with the fire stuff around the marker) that come from your non-starting city, but you can do all the misc. quests.
You can't do 'main' quests (the ones with the fire stuff around the marker) that come from your non-starting city, but you can do all the misc. quests.
