Profession liberale to gite

This is several questions in one, so:
CONTEXT: My husband and I moved to France from the US 18 months ago on autoentrepreneur (profession liberale) visas. We now have our first CdSes and our cartes vitale. My business has done well, but my husband’s cannot seem to get any traction. We are considering purchasing a rental property (which is already profitable under the current owner).
QUESTIONS:

1. Can he use income from the rental property as income under the AE scheme to maintain his visa status? If not, do we have to start over? (Yikes!)
2. If he’s changing the nature of his business (his original business plan involved tech consulting and editing), are we required to communicate that to anyone? (URSSAF? OFII? The Prefecture?)
3. What is the recommended legal form for purchasing the property? (We are married with many adult children and stepchildren in the US, if that matters, and his health isn’t stellar.)
4. Does purchasing the property jointly, while he manages the rentals individually, impact any of these considerations?

I’ll probably have more questions, but the notaire wants some answers from us quickly on the legal structure. Thanks for your prompt response!
(And thank you for your stellar help in the past. We consider your assistance the primary reason we’ve been able to navigate this bureaucracy, so we’re incredibly grateful for your expertise.)