I approached a lender with 4 properties in the very beginning and was denied.

It may get denied, given the circumstances, but it is silly not to try.

I'm fine with slightly less ROI if it means a better credit tenant who I sense won't be a problem or abuse the property.  

We have found one location 100 ft from a bus route, that goes to the front door of the airport.

That part is irrelevant.You could deny they move this person in, but they'll probably move him in anyway.

Anyone that denies this is delusional.

2. can a new purchaser denied from purchasing new policy ?

Thank you very much for your invaluable information, thanks to: Jaron Wallings, Steve Vaughan, Christopher H, Denis Nguyen and Joe Biscaha for being here as advisors on the bigger Pockets Family.Thank you.

Quote from @John Hernandez:  If both sides consider it a “deal” then fine, that is capitalism at its best.this is the very definition of a marketplace. now - if the 'willing' seller is misinformed, disordered or ignorant, and/or the 'able' buyer is misleading, fraudulent or abusive... then the definition is on a slippery slope.these are matters for the conscience, and pure pointers of character. !

Tenant fills out app and pays fee,   you screen in the software, deny or accept.