I have "Move to attack/use" enabled in the options. After four hours of playing my first game (with permadeath), I was in Brox's shop and moved to walk out. Brox randomly moved in front of the entrance (I didn't even know he could move) and my character moved into him, causing him to attack (I didn't even know Brox could be attacked). Brox attacked back, and I died in one hit. Clearly, moving into Brox like this should invoke 'use,' not 'attack.' I am severely pissed off at this game right now, it is not fun when all that time invested is cheated away from you for no reason.
No, I only bought one thing the whole game. I'm not sure how to steal even (the only skill points I had anything put into were smithing and berserker-rage).
You can always pick up an item by clicking on it and clicking "Pick up", then Brax moves in front of the exit to keep you from leaving.