However, I also don't know if having so much credit relative to my income will have an effect on my ability to get approved for a loan to purchase a property or a refinance option.

My vacancy rate is effectively zero.   

Meanwhile you, the owner, are stuck with no income, eviction expenses, lawyer fees, maintenance and repairs, taxes, insurance, loan payment, city code violation fees and vacancies.

On the other hand, if it was the seller asking, I would recommend against it because it will effect the rates on their next policy on their new / future home(s)

I also can’t imagine how that would come up as an issue - and would likely be a tough answer even for a lawyer)

Whatever the last lease they signed is what is in effect just one a month to month basis. 

I have buildings at 100% and buildings in mid 80sThe hurricane didn’t effect me at all.

Door knock is most effective. 

@Denise PauzanoNot a lawyer-https://www.nolo.com/legal-encyclopedia/eviction-notices-nonpayment-rent-pennsylvania.html That says 10 day notice to pay or quit unless otherwise specified in the lease

In some cases, the effective tax rate is huge.