As an example, we decided to replace the windows in a house we were renovating and ended up costing us $50,000 extra because we got into issues with permitting and suddenly found ourselves having to hire an architect, speciality contractors, etc.  

Taxes depend on the gains from the insurance payout and sale relative to your adjusted basis.

The main issue I have is contemplating the baloon payment at the end of the 2nd year and refinancing the remainder with a bank...how can I compute that into calculating the IRR?

@Kyler Tarr it's good you haven't had an issue but you also mentioned your property has some knob & tube.  

We currently use Hospitable for 12 properties, and it's working fine, no major issues, and I know they've been expanding with new features.

With your construction background, you're already in a strong position to add value to properties through renovations or identifying potential issues.

Getting more mortgages does not help me with the two issues I outlined - spending less time on real estate and freeing up head-space.

Their target audience are professionals with cash don't don't have the time or desire to become educated and are willing to pay/forgo some revenue for a experienced investment relations firm. 

Are LPs entitled to see foreclosure, bank loan related docs?

Also, keep in mind that if you do self manage, you do put yourself at more risk for a legal issues.