I think you are right to be concerned however the chances of going from functional home system to emergency fund draining non operation in six months following an inspection are pretty low.

It included all new drains & O/flow from the tub, all new shower/tub fixtures, a code required expansion tank @ the HW tank & a code required back flow valve at the water meter. $4,900 & they did an amazing job.

Does the soil drain well?  

I know others are suggesting eviction, but that will just cost you thousands, plus it will be a major time drain.

I assume the buyers wife was pleased as she probably appreciated the age & condition of the absconded appliances.Worst one was many years ago when the evicted tenants went to the trouble of draining the furnace oil tank into 5 gall containers. 

The inspection I had done was solid, I am mostly concerned about the sewer and drain systems, are these even covered in the home warranties? 

(Water supply from the main house, a new drain, a small electrical panel, outdoor washer/dryer).The question is...what's the best way to move forward?

Painting the basement walls with waterproof paint has done wonders for a problem that has existed for almost 20 years (a bit more updating on the the gutter/drain system is still in the works).

Another time, a tenant let me into their place and showed me a leaky kitchen faucet that had dripped down to the apartment below and caused water damage, along with a few other minor issues like long tears in the carpet, a broken drain in the bathtub, leaky windows and sliding glass door...  

i'm thinking of making one with poured cement as its for outdoors in a private spot in my backyard (very simple, open, like the type near beaches and pools, but i do want a pan so i can redirect grey water down the pan's drain to the area of garden i want it to go. yea i like to take showers outdoors in the summer instead of tracking dirt/mud into the house, as am an avid gardener and it reminds me of my vacations overseas of which these days it doesn't look i'll be going on anytime soon cuz of my finances =/