When I've talked to the owners, they said their tenants are not problematic.

Talk to the exterminator and let them know there is a problem. 

Talk about some happy families.

As long as you don't explicitly talk about your current offering, you are in the clear."  

The only thing we can think of is he deals with a lot of international trade and money and maybe it’s OFAC we just get a scripted message every time we talk to someone so we got lawyers involved. 

Are there other players in this field that I should be aware of and consider talking to before making a final decision?

Or are you actually talking to a bank about buying the note so you can see the notes and credit on the owner of the property?

So was the house I am talking about. 

Also, since you are unrepresentated, you can talk to agent about the buyer commission.

Unless you are talking serious money, which I would say is 2k or more in excess taxes, it may not be worth your effort.