I'm an Airbnb host in a major city (Philly) and ever since the covid lockdown started, I've gotten a lot of booking requests that are really weird because they all have the same red flags in common.

She currently is an investor herself but most of her properties are in Nigeria and she is breaking into the American market so she gave me the push also.

In many cases, Airbnb hosts are not required to make their homes compliant with the standards set out in the Americans with Disabilities Act (ADA) .

It's a red flag.

And, my leases state no window coverings such as sheets, flags, etc allowed.

Maybe review your screening procedure to see where the red flags were, if there were any you missed. 

If I'm a credit card company, there's no way I'm approving those credit line increase requests when I start to see the amount of unused credit available to him approach 50% of his total student loan balances, MAJOR red flag.

Free money( match), diversification in asset classes, stocks are very liquid, very passive, tax free growth (Roth), belief in capitalism and the American company, good solid return history, cheap entry with ongoing contributions, etc. 

@Renata Johnson,I feel for you,  but the red flags were waving high! 

Regarding closing costs we use First American Closing Cost Calculator.