The details of the circumstances will dictate what to do  I stay out of stocks for the most part.

I'm a newbie I don't have any "doors" except my own condo which I've had over 7+ yrs but I'm working on getting educated now so I can one day (sooner than later) I can fire my boss as well.

Under the circumstances that you described, there is almost no chance the seller will attempt to force your purchase. 

There were many months where this stupid note was costing me 1-2k a month in legal fees (and due to the circumstances yes, we had to go forward) and the old cliché about "you only need to set aside 3k for legal" would have sent me straight to bankruptcy. 

In most circumstances I agree that abatement is cost prohibitive, overkill, and frankly not necessary.

He has no family and basically stays shut in except to pay bills or grocery shop.

C class = older units, typically 30-50 years old, lower to moderate income levels, very few amenities.D class = very old, no amenities, high crime, poor neighborhoods and school rankings, low income residents, mostly subsidized housing residents, etc.Again, these are general interpretations, there are exceptions and no hard rules.

Some property managers have clauses in there that make it exceptionally difficult to end the contract if there is a tenant in place. 

One other exception is if you're in a very high demand / growth area such as San Francisco.

I agree with @Greg Scott except for the $125 - it's $500 per year plus $20 for doing it online.