I agree that is will be a gamble as to how well it will do.Also, ask the owner if they will entertain partial owner financing to keep from dragging family and friends into this risky business venture.Maybe even rent from owner for a year with right to sublease to see how it goes before committing to a purchase.

ALL of my major problem tenants happened to have had a average (adults in the household) score below 625. 

You don't think grown adults who cannot (or will not) pay for their own housing are statistically more irresponsible than grown adults who do pay for their own housing?

Would you entertain a condo?

Closer to entertainment district, services and mass transit.  

(yeah, maybe I shouldn't be broadcasting my sick twisted forms of entertainment and strategy should I)BUT, most importantly is KNOW YOUR MAO and follow the math. 

My personal example is a one bedroom condo I’ve held my entire adult life - and this is in a top tier market - Dupont Circle neighborhood in Washington DC.

If he qualifies, create a new lease with all adult occupants (and a sublet provision) and get it signed and place it in a known location.good luck 

Over half of the things you said were literally false accusations based on your emotion on the situation and I’m not entertaining that of course.

Be conservative and don't rely on young adults to pay their rent.