Initially, our plan was to fix the drywall leaks, clean out the property, and relist it for a small profit.

We've installed the Moen leak detection device, which detects leaks both hot water and cold water, and monitors water usage and gives you weekly reports.

Is there a pipe leak that is softening the soil anywhere nearby? 

Now maybe I am wrong and all the POH homes are spectacular and very well maintained with new roofs, furnaces and no water leaks. 

I am guessing that the vast majority of homes 10+ years old had some sort of water damage at some point, most had probably several.My own home is only a few years old and we had the washer spring a leak and a few years later the RO system in the kitchen started leaking into the cabinet.Seller disclosures are pretty useless in my opinion.

Spend what’s needed to upgrade with reliable mechanical systems, roof that doesn’t leak, remediate all mold; interior design modernized; in other words a place that will attract a higher income no hassle tenant.  

In terms of maintenance, they are generally safer because you are not responsible for the exterior and common areas and potential leaks, etc.

Want to buy an old commercial building or gas station that had leaking PERC or leaking gas tanks? 

We have had these type of leaks lots of times.

The inspector wanted me to add 2 screws to anchor the condenser and he did check for leaks at the gas connection (the gas connection that was flagged was decades old and I questioned if was before a permit was required but city stated it was up to me to prove that it was there prior to permit requirement).