A flipper I know didn't follow his recommendation and applied Killz (water based in CA) and during Realtor walk through, prospective buyers complained of cig smell.

You need 2 hvac systems , 2 electric meters , you should split the units and submeter the water .   

For example, a hot water heater is ready to go versus a bathroom you want to upgrade.

We have had two different contractors try to fix using various types of cement/epoxy while digging up outside area and they can not seem to get it right but have decreased the water a bit.

Certainly replacing a furnace and/or a water heater would require a permit as well as running a new or replacing a duct run.

For example, if a family is displaced due to extensive water damage that will take a few months to repair, the insurance company will then look to find temporary housing for their customer/displaced family.

We are leaning towards testing the waters for putting it on the market even though originally it was going to be a long term buy and hold.

Water, air, sewage?

You may be dead in the water. 

I usually fly fish Cosby Creek, and have seen 2 other fishermen on that water in 19 years.