The tutorial dungeon really isn't that long. I guess it depends on team set up~ but I made a healer with a staff. So I used her staff ranged attack to break doors (no durability loss) or as suggested above. Use bare hands ^_^
Yeah, that needs to change. The fact that spells can bypass durability loss and make the lockpicking skill pointless is not good at all. Yes, the same can be done with weapons, but there is a cost (and frankly the cost should be higher - damaged weapons should sell for less money to the vendor, in my opinion).