I am assured that this time, a little bit of modesty will not prevent us from finding out. 

I have owned rentals for 19 years and I can assure you the State of California and it's tenant friendly laws limit how much control we really have.  

Code compliance probably got the address from the appraisal district.

The seller is required to certify the septic is in compliance and that is usually accepted as rote, since they provide the certificate from the septic inspector.

You've provided such a great perspective on this situation, and I can't help but to nod my head in agreement with everything you just re-assured me about!

If you search short-term rental on their website, you'll find more information, or call Code Compliance for the rental inspection requirements.  

County tax rolls may say market value is only $50k, but rest assured when the county finds out it has been sold for $100k, your taxes will be double next year.

Check with your CPA to assure you are having this set up like you want.  

They are readily aware that tax recovery amounts are significant in these areas, and given the increased focus on revenue recovery over general tax compliance I would conclude that this focus will only further intensify.

The real estate commission can and will do an inspection of your home office with little to no notice to make sure you are in compliance with the law.