What I enjoyed a lot in Oblivion was after I bought a house I would find a item or secret passage in the house that would then trigger a quest and give me the history of the house, which would give me a sense of belonging to it rather than just another place to store my stuff. So far I have 3 houses fully upgraded and I have yet to find anything like that. The nearest thing I found was in the rifted garden there is a barrel that belongs to the thieves guild and it refills with random items every so often but these barrels are located all over Riften and are not unique to your house.

Has anyone else found a quest inside their house once it has been purchased?

No one else care about the lack of house quests?

I care deeply.