If they break up, he's still the legal tenant.

As a part of my preparation for the purchase of my first investment property (shooting for next 9-18 months) I still have a lot of work left to do as far as research on the legal side of things, landlord/tenant contracts, owner financing options, etc. etc. 

I can get pre approved for a 15% down payment (but I plan to do 20%) owner occupied purchase + rehab loan.

MLS allows non-realtors to have access to MLS legally.

I don't want to find a tenant and after the terms are up, and they still can't get approved for a loan or can't qualify to purchase the property.

Additionally, I'm not even sure how I'd tackle that legally if I did try to recoup any unpaid rent from three different cosigners. 

Legally, they have breached the contract and if you take them to court you'd likely win. 

Maybe you should be sure that is the real reason -- maybe they have outstanding legal cases with the seller. 

I’d love to legally rezone it to a two flat and renovate the addition but after talking with the secretary at zoning downtown I thought I better post the question here first.

@Bill Thomas BP keeps all legal forms under the Store directory.