And I send anywhere from 50 to 150 to Owners at every move out (or new takeover), and at least a couple dozen from interim inspections, avoiding as much as possible, photos including personal property and people.

This home has been a huge undertaking with comparables showing lucrative results on the sale priceWould this be the time to assess our future, whether to sit tight and try to expand.

I have yet to see the connections of cast iron not greatly reduced on diameter on any property that I have had scoped from early 1950s or older (likely more than a dozen scopes).  

I’m getting a foundation specialist to go out and assess the damage, but their best interest is getting my future business - not advising against a house with settling problems.

The other thing to consider is there may be special assessments especially in these older high rise buildings.

Your assessment is based on your PP, YES you will pay more because you paid more.

My question is, having no way of knowing the quality of screening the current tenants would have actually undergone, can I use the information on file to run a quality background and credit check to perform a "risk assessment"?

We have purchased a half dozen foreclosures in the few years and I can speak to the buy side and some due diligence best practices if that helps.

When assessing low-income investment opportunities, I use 20% and sometimes greater as a more apt vacancy rate to account for the higher rate of non-payment and vacant units. 

I typically agree, but was wondering if the assessment changes when you're comparing a dense development where no one is going to have a typical front yard anyhow (think townhome cul-de-sac with a more narrow street).