Why needed mob respawn? This is not a grinding game. By just killing all available and completing side quests, you can reach all the levels needed. If I want to grind, I just go and install a mmorpg and start off with it. It will make situation more troublesome, eg when I need to retrace some locked chests in some already cleared dungeon, I will need to fight the same old bunch of douchebag again to reach the chests.
