I don't think deleting the doors would foil the repoman. I've never tried it, mind you, but I did once use that as a strategy to try to keep burglars out. My sim was very poor and couldn't afford the burglar alarm. Every night I would move the outside door to an inside wall, feeling very proud of my solution. Until the burglar came and pulled out some kind of super-vacuum that sucked up stuff right through the walls. If the burglars have such equipment, I would expect the repoman to be able to do this too.