Interest rates are high relative to house prices, this won’t last forever.  

The other thing is whether or not you plan on living with your inlaws forever.

CA's Secretary of State forms list the name and address of either a manager or member, so unless you're hiring a third party to serve as manager of your LLC, anonymity is very hard to achieve once filing publicly in CA.As to the probate part, you're right that going through a court probate is a huge hassle, including being expensive and time consuming. 

Example:  California has been in a drought forever.  

(I'm sure both the average consumer AND the average entrepreneur would disagree, of course, but hey - y'all're the guys with the fancy, big money jobs and the college degrees - what do I know ...)

Flat fee brokerages have been around forever, as low as $295.

It could all go to nothing, but This also could be the internet of money and will forever change history.

They got fundamentally sound real estate, with matching debt (10+ yr fixed rate) and budgets with the intent to hold nearly forever. 

Kiavi is forever contacting me to bring them deals..

I probably wouldn’t mention your third point - it makes it sound like you expect them to hold this note forever and I’m not very certain, but I’m guessing there isn’t a huge market for $100k secondary notes.Have you considered asking them to finance 90-100% for a short period of time so you can rehab and refi at a higher valuation?