Evolve seems like they charge less but a homeowners have to contract with a local cleaning crew and maintenance.

Tenant will also be responsible for the additional cost of any legal notice.

The first being - don't bring your friends or family into the mix :)Since it sounds like you're pretty solidified in your friend moving in, and it could be a good first roomie, so just to get your feet wet... i'll double down on Laura's advice - do a lease, for the legalities, but i also highly recommend some sort of written (we call it a) Room Mate Agreement.

I assumed once I signed the contract, I owned the property, just land at that point, and have a contract to build the quad.As for if they run out of cash at 80%, I could close the gap if absolutely needed but obviously that isn't the goal.The builder owns the entire development, minus the handful that have/being built, so they have a vested interest in this working, they want to do it a couple of hundred times at least.

@Jeremy Bloom  the rag on the thermostat can be beat by placing a remote thermostat that is set to the legally required temperature with that remote thermostat actually controlling the temperature.

Finally- you can eliminate 95% of the troubles and risk by simply having professional and legal screening and management processes, so don't sleep on that piece. 

Quote from @Corey Gelineau: The inspection contingency is used to legally back out of a contract due to the property being in an unacceptable condition upon inspecting the property.

3) how to manage the contract renewal and define the new rental value.

So he sold his business to them and signed a lease contract with them and now selling the building.

Also, how did you come up with your own purchase contract?