I signed a very basic promissory note listing the property address, but I don't think it will protect me if something goes sideways.

Basically they do the same thing or sometimes they sign a lease with the landlord and move while the squatter is still there; they occupy some part of the unit like a vacant space (basement), living room couch showing the signed lease from the landlord :-) (squatter don't have a signed lease so this new guy with the signed lease is actually has the right to stay in the house), play loud music, talk too loudly on the phone, watch TV while everyone is asleep etc. etc. so the squatter gets fed up and decides to leave.

My partner and I have a document we work through to analyze deals.A structured Excel template for real estate deals which includes: basic property info like address, type, size, purchase price, and closing costs.

Yeah for small multifamily, ARV is basically stabilized NOI divided by a cap rate, but the cap rate is the whole game and it rarely comes from perfect 8 unit comps in the same few blocks.Most appraisers I see will triangulate it using any recent sales they can support, even if that means 4 to 6 units, 10 to 20 units, nearby neighborhoods, and older sales adjusted for market movement.

Hopefully that will do the trick 👍🏻

This is very basic knowledge, even among people who don’t invest in California.

I'm in the process of learning as much of the basics as possible before I dive in.

Looking at possibly exiting if interest rates go down since prices will most likely go up and the profits have basically been cut in half over the last 2 to 3 years and that's with self managing...I'd lose $$ every month if it was managed.

That is a basic tenet of project management and something many investors fail to appreciate. 

However, you need to understand basic fundamentals. higher returns means higher risk, effort and/or barrier to entry.