I need to update the outside, new paint, replace some wood rot, etc. as a first priority. 

The roofer said they never reinstalled the skylight surroundings during roof replacement and new installation.

There house is in poor shape and I've been suggesting that they consider repurposing the land to replace their home with a few multifamily units. 

You might say you can do things like change a faucet, change a toilet, replace a P trap, etc.

Of course you want to keep it liquid so you have it when it is time to replace something.

The contractor that we've been working for month has had AC coil replaced to a new one as well as organic chemicals sprayed into the system, the procedure was performed three times and helped for a short period of time.The issue that is being described here is also known as "dirty sock syndrome". 99% of the time it's getting solved with coil replacement.

I had the sellers redo the power panel, replaced the AC and currently, renovating the rest.

@John Warren FYI, HUD eliminated the Streamline 203k back in September 2015 and replaced it with the Limited 203k, which has similar but different guidelines.

I’m actually replacing the roof once i close on the property.I was thinking of refinancing quickly in 1-3 months with a hard money lender that’s offering me. 6% interest, then wait a a little more (like a year or so) to refinance through a bank with a lower %. that would get me out of the original loan faster and have reserves, could also reinvest some of it into some flips to keep paying off the new refinance loan.But thank you so much for your advice, it was helpful!

This means that in a game of chicken with two ultimatums, the landlords will usually "win", in the sense that they will wait out the non-payment, evict, and replace.