I definately like a durability system. Sadly with the, imho, quite crappy controls of characters and inventory (can't select multiple characters or do things simultaneously) it's indeed a PITA. So there's imho the place to fix it.
As for the "%-chance to break irrepairable weapon on smashing doors/etc" idea... HELL, PLEASE NO! Why? Well... break, reload, break, reload, break, reload... I think you get my point. That's bad enough with the loot RNG already. Plus... how much integrity does the game world offer if your steel sword breaks hitting a single wooden door but you can slay a hundred adamantium golems with it? Thanks, but no thanks.
