I have a method that I'm formulating, but it is very data intensive (requiring web-scraping and statistical models), but a "good enough" solution could save me a lot of time.

Getting quotes alone often requires multiple calls, and as consumers, we haven't experienced the level of service one would expect.

Any other surprises such as higher tax rates, preservation requirements, flood insurance, etc?

My SOP is to contact the current landlord and employer, require proof of income for the past 3 months, and use Rent Spree for background, credit, eviction, etc.

No requirement if paid by credit card.

However, you had better be certain that you followed the requirements for handling and deducting from the security deposit after move-out required in your state.

Marketing a property effectively becomes solely your responsibility, requiring you to explore various platforms for visibility, which might not reach as wide an audience as a professional's network would.

No digging up of the yard or concrete patio required. 20 year warranty.

Using this strategy your tenant-buyer must put up at least a 3.5% downpayment (required for an FHA loan), non-refundable. 

The tankless models will often require some keyboard attendant (that was me) to run interference and get stuff going again.