You guys aren't helping much. 

If they aren't paying, they should be evicted.

Honestly, if you aren't looking to sell real estate, use the materials as a learning resource and work on finding an experienced investor friendly agent that you can develop a long term working relationship with. 

No, lenders aren't going to discount an assumption.  

If the tenant owns the dryer, then you clearly aren't responsible.

Dishwashers aren't magic. 

If you use quickbooks payment feature, and you see anything shady going on with bill payments, contact your tenants/clients immediately to verify that they aren’t trying to pay multiple times with the same information.

How do I ensure he owns the houses and they aren't still financed?  

Markets just aren't that demolished right now to be able to build that strong to give that big of a boom.

You also provide a very tangible service, housing...a nice change from abstract jobs where the deliverables aren't as clear...Granted, you can't control some market forces and even real estate has gray areas (like you do to all right but still run into issues ) .