There are a couple of credit unions and small banks, which I can join to use their business banking services, even though I am not a resident of TN.

Any tips?

What resources do I need to effectively screen tenants, how do I run their credit or criminal history?

My credit is at 650 and his is in the 500-550 range.

After a guest stole out TV's and filed a claim on their credit card payment - and VRBO did NOTHING to assist us, we checked out what Airbnb would have done. 

By following these tips, you can make an informed decision and ensure a successful investment.

The seller has agreed to give a credit of $7000 and price reduction of $5000 for window repairs after closing, this would cover the costs of replacing the windows that are in the worst condition.

I paid by credit card. 

Also any reputable lenders able to lend on property than investor credit?

I own one on an agreement for sale/executory contract, but that was to help a veteran family that was active military where the deal made sense and everyone had good credit worthiness.