Specifically I will look into the following:- Legal- Tax Rules- Network + Friends + Connections- Language Barriers- Payment Transactions and Recourse for Fraud- General/customary behavior among vendors and contractors in the area (good and bad)

I never understand people that dog the *voluntary* sites they participate in; if things are so bad around here, why not just leave and go somewhere else? 

Even with vetting guests, they still sometimes break the rules and bring large dogs or have parties. 

Your tenant is not paying rent as agreed, so you want to pay him money for his bad behavior?

If I say I will pat a bird dog for properties I purchase, I do.  

So for you maybe you figure out how to do this and bird dog for actual note buyers and see if you get any traction ..

I told them puppies and unfixed dogs would be a no-go for us. 

@Travis Bobo  the written gurantee is WORTHLESS  they just fold up and move on.. what are you going to do.. there is no free lunch in real estate and there is no buying your way into success its earned and its dog tough do not let anyone tell U otherwise.. listen to Steve he knows as well.. he is a for real investor who does deals..

Now there's only 1 or 2 of them, plus a few males, 2-3 dogs, and there is sad looking traffic going in & out of the house.   

Ask about their payment punctuality, behavior as tenants, and reasons for leaving.- Since they have been paying taxes for eight years, request copies of their tax returns for the past two to three years.