I do income potential reviews for clients all the time, every market has subtle differences but these are generally good indicators. 

Also, it’s interesting to note that not maintaining corporate “formalities” is one indication of “disregard”.  

The fact that you are thinking about it may indicate the property is more stressful than it's worth.

Some will indicate risk margins - even though flips like the ones in your area aren't impossible, on your proposition the risk factor would be through the roof. 

@Aaron MaxwellThere is publicly available data that will give you an indication of growth in an area.

I have asked if they feel unsafe but I never get a straightforward answer which could be indicative of one of three reasons you stated.

There's plenty of posts in the Philadelphia forums that highlight the fundamentals that are the stronger indicators of appreciation.

You agree to pay the monthly Rent indicated above via deposit to the following checking account at XYX Credit Union: account # 123456; routing # 123456  (nearest branch is 123 Main Street, CITY).

There was no reason why indicated nor anyway to contact them listed. 

The fact they were sketchy indicates they are trying to pull one over.