Confused about party mechanics

[surrel]

You have to hot key the limit break skill. It's under actions or skills or something like that in your menu. Anyone can use the limit break once the bar has filled up but regardless of who does it, the bar will be used. It's shared among the party members so its best to decide who will use it and when.

Once you exit the dungeon, you're already out of the party, unless you actually formed a party with someone..then you'll have to leave manually.