The Philadelphia rental market remains strong, especially in high-demand areas near universities, hospitals, and transit hubs, so vacancies can generally be minimized with the right property in the right location.

We have parted ways with a bunch of "STR slumlords" as I call them but still some cheapskates remain.

I am remaining diligent with this project because I am rusted around the joints.

Just don't change your address to your parent's house, that would throw up a red flag. as long as that remains your primary and you aren't renting it out for at least a year after purchase, there shouldn't be any issues. 

Just trying to find out how to secure remaining 20% for seller

I actually got an option from a buyer to buy all of my remaining properties in cash.

You should most likely price it at a return of 8% to 12% depending upon remaining term and payment history.

Don't just call them once... make it a point to remain in regular contact with them (at least 1x per month) via phone, face to face, email, text, social media, mail, etc.At the same time, make it a point to add X number of NEW contacts to your database each day or week.

And if they use public funds the property has to remain affordable housing for THIRTY YEARS which is insane.

It really can be the best of both worlds—remaining a passive investor while still getting the ROI you want!