What is your primary reason for wanting to pay off the mortgage? 

Quote from @Benjamin Blunt: What are the best strategies or tools that you use to find Off-Market Properties?

I'm with you that sidewalk slip and fall litigation may be less likely in the Midwest than say Mid Atlantic which tends to have more litigious cities but dismissing premises liability issues can come back to bite an investor and when these properties have such razor thin margins that an investor must consider the cost benefit analysis of safety against ROI, there is a real estate issue and is usually a losing proposition.   

Hey guys if a city worker who can buy properties for half off on the land bank as part of there benefits would it be worth it.

Over this time I have acquired my contractor team and have vetted them through my job as a property manager, figured out my strategy(Off Market/Deep buying) and location.

My parents have finished paying off the mortgage on their home and are wondering weather it would be more profitable to sell their home or rent it out. 

A paid off property throws off more cash than a leveraged property.

In Philadelphia the fundamentals are strong: leading industries/employers are in the Education and Medical fields which are known to be stable, proximity to NYC and DC, national airport, port city, affordability compared to mid-atlantic predecessors.

I posted a sign to turn off gas as a reminder in the kitchen.

The wealth generator, the thing that one can live off of, retire off of, is the appreciation and how one leverages and tap's into it.