You might be able to afford a "better" property then.If you invest somewhere else in a vacation rental for example, you might also discover another place that you might like for retirement as well that might be more profitable.

The company “cares about its tenants” and believes in providing “above standard living conditions,” it said in its statement.Other Philadelphia properties owned by RAD or the other businesses have been licensed with L&I as vacant real estate.

All fees seemed right in line with industry standard, ($9.95/mo, per entity + one-time registration fees). 

I know property managers in every state who use non-refundable application fees and it is the standard for every class of property and applicant.

You have set your standards.

Property values and interest rate (but with higher standards) were lower in 2012 than 2007.In general it is often true, but not always.  

So far the concerns I have discovered would be things like control of collateral, maintenance requirements/margin calls, and various fees that may be charged on quarterly or annual basis.

Standard stock is fine.

Looking at this mathematically, if you assume a 50% non-renewal rate (industry standard) and use the low end of the range of $5,000 per non-renewal, there is a loss of $50,000 per year on a 20 unit property.

After that make sure you have your property up to standard before placing a tenant.