You are stuck in WoW-like and EQ-like games. Free your mind, imagine something else. Reminding that Fallout has a post-nuclear setting. It haven't neither a developed building industry nor estates market and rielter offices. Who will sell you a house? Good question, but the better one is: Who will sell a million houses for all players? And the answer is: nobody.
If you want to have a house - build it. Find a proper location, gather enough resources and find a player with proper skill (or raise it yourself). But building a house somewhere, you are declaring: This place is mine! So be ready do protect your property. A lock on the door for the fair visitors, a dog (or maybe a turret) inside for the thiefs, and so on.
Thinking about stealing and lockpicking, do not think about dangers for yourself (jam your hamster instinct), think about opportunities for the gameplay process. Remember that the developers will not forget about balance, all players will have approximately equal possibilities to get and keep their goods. Excuse my bad English... I am a Russian bear, it's hard to type with claws.