My thoughts:
Each of the Baldurian backgrounds have a connection somewhere in town. Entertainer may have performed at the blushing mermaid, urchin knows a couple of homeless people and can get a little extra info from them, etc. For nobles, you don't have to be the head of a house/family. You could just have a room in a manor that your relative owns. I think little moments like that make more sense than trying to implement a house for everyone based on their background.
