There are tricks to thwart this.I am not proceeding with a rental agreement without speaking to two real people who have had personal experience with the prospect: the landlord and the work supervisor. 

Not sure IF all title insurers will issue a policy in EXCESS of the purchase price to cover the extra padding (wholesale fee) I was looking for a way (out of the box thoughts) to possibly FORCE this original Lot owners hand to SELL the lot back to our friend or thwart him from selling the lot to anyone else.Some thoughts;Acquiring any future past due HOA Dues from the HOA (then bringing action to foreclose on them)?

Sticking to your approval criteria and treating everyone the same thwarts that from happening even unintentionally. 

Quote from @Eugene Weixel: Is Morris presence in Portugal thwarting the New Jersey lawsuits? 

Putting more down payment is a way you can make the numbers work better but the more you put down the closer you are to conventional financing and thwarting the benefit of low down FHA financing.The SS rule requires that the gross rents of all units even your owner occupied unit X 75% is greater than your monthly PITI (prin/int/tax/ins monthly payment).

If I am inferring the meaning correctly, then that has been one of the more benevolent scams that I've managed to thwart with my mother's house!

They can make plans to thwart the sheriff (or otherwise screw up the unit). 

It sounds like your seller is knowledgeable and trying to thwart your efforts.

In the end, he left after 4 years and after remodeling it the sale was thwarted by the new buyer's real estate attorney who required a "quit claim" from the land contract person.

We had a problem with them stealing light bulbs out of the laundry and hallway areas, so I had the bright idea (pun intended) to install yellow "bug light" bulbs in an effort to thwart this problem.