Instead of durability and repair hammers, we should have a Disarm and Disrobe status/effects that allow an enemy to strip your gear(forcing AP use to re-equip), and Crowbars that act like super-lockpicks(rare, but require no skill to use).
With Crowbars in game, no door should be breakable through damage.
It achieves the same thing durability does: you can break things(gold cost) instead of opening them(skill investment), but it does so without the middleman of gear breaking and requiring repair.
That's simple and easy to understand, and it probably allows for better management of doors which you don't want players to bash down too easily.
