Philadelphia's population growth was about 4.4% and other cities like Brentwood and McKees Rocks saw a population decrease of -11.4 and -11.6 respectively.

Too many people unfortunately in todays world do live paycheck to paycheck and are unable to save up to owning simply because they are undisciplined when it comes to money. 1st financial law from the book "The Richest man in Babylon" : one's "necessary" expenses will increase AND decrease in DIRECT proportion to ones income.

The mortgage insurance costs for FHA decreased, and interest rates are lower now as well. 

Van #'s show the population decreasing.

Do not buy anywhere if the state or metro populations are static or decreasing.

When rehabbing, keep things neutral and don't get weird ideas and try to implement funky project ideas- these slow you down, decrease the breadth of appeal to wider buyer pool.  

Most people would suggest jumping in and beginning this right away in order to immediately decrease their living expenses.

This means that every $5/month on your monthly debt decreases your maximum purchasing power by $1K. 

The number properties would only go down if cash-flow increased, debt decreased, or properties were paid off.

I could see someone getting a serious muscle tear or dislocation maybe.