Make battles universally last for 1hr and show a bloody progress bar with time remaining on each battle, as well as a bar for inactive zones that shows how long until the zone will see another battle.

Nothing is more frustrating than warping to a zone as the monsters are leaving, or warping in and tagging up only for the fight to last 5 minutes. It's bloody annoying.

The time sink and difficulty should be in the content, not waiting for the content or trying to find the content.