Insurance co's are offering hundreds of thousands in liability protection for 10s of dollars per month to you personally already. 

Buyer is getting one hundred percent new house.

We are cash flowing a couple hundred a month and will hopefully not have any major maintenance headaches for the first few years.

Not sure how much money they put in but looks like flooring, cabinets and painting.. they had this listed at 650K in September.

i said, go ahead and buy it and do it yourself lol....then he asked if he could use my cabinet guy, contractors, and hard money lender....wtf

More like $15 if I can keep cabinets, tubs, vanities , Etc. 

I prefer oak kitchen cabinets.

Just like analyzing deals, analyze rehab costs a few hundred times and you'll get some precision. 

My first draft of a plan is to borrow in the neighborhood of $150K from an investor, put 5% down and live it in myself, and build a backyard ADU while putting sweat equity into the main house through tiling, replacing/refinishing cabinets, installing new flooring, etc.

I don't say this to dissuade you, but I was making hundreds of cold calls a day for months and didn't land a single contract.