The property now cash flows $4,550/mo after all bills are paid.

Now here is something that I hope changes.

We have renters there now and they cover the mortgage with a bit of cash flow ($100/month), but the property is going to need some more major updates (windows, roof, HVAC, siding) within the next 5 years as they are starting to be at the end of their useful lives.We would like to pay off our primary residence as quickly as possible to “free us” from mortgage payments on our primary residence.My questions are below:1.

outright flips are very, very difficult right now. 

You should always talk to a mortgage broker or bank first to find how much you qualify for before starting the investor journey.

Now you can always rent it out and just keep it on the down low but just be aware of the risk.

Has become part short term and mid-term rental now.

(2) some fantasy that they’re now “their own boss”

If the zoning map was altered where all 2-4 units were now RT-4 then developers couldn't just tear them down to make SFH and building owners wouldn't need to fight the city to increase density. 

Right now the market in Pittsburgh is pretty good for picking up small multi-units.