Pictures can hide a lot in a house.The numbers can say whatever you want them to, but that doesn't always happen in reality.

Ikea cabinets, granite, stainless, pulled up the tile, and managed to salvage the hardwoods hiding under 2 additional layers of terrible linoleum.

It is however the most inefficient way to grow wealth short of hiding it in your mattress.  

If you want to hide behind a property manager, then go hire one.

If not,dump it and get something new and modern.A sellers disclosure is the paperwork from the seller telling you everything they know for a fact about the property.If they know about any defects that might affect the value of the property,they must disclose it in writing during the inspection period.They can not hide anything from you like a known roof leak,bad plumbing,rats and termites,etc.Before you proceed with the sale,I would have a serious talk with your Realtors,contractors,and mortgage lenders about whether this project is going to be too much to handle and still be affordable when the work is completed many months from now.

What else has this seller failed to disclose or hide at the last second??

If you had a contract and you didn't hide anything, it should be valid.

The garbage-y smell you are describing sounds like you might have more rodent nests hiding somewhere.

I understand wanting to be the nice guy, but this guy squatted without your permission and he did it on purpose.All red flags.What else is he hiding?

I tear a tab off the box with brand and model number and tacking it/hiding it behind access panels/under sink tacked up.