I put an estimate of about 65-100 PPSF (this is a wide range due to location and unknown workload amount for the contractor). 

This is super helpful as your story really connects all the unknowns in between each task. 

He's just starting probate, so there are lots of unknown unknowns.

Too big an unknown.

The one important piece of info that we don't have here is what is the actual capital gain (difference from what they originally paid to what the sale price will be (unknown until it sells obviously), minus capital expenditures (improvements) and other expenses like selling costs (commissions/ seller's closing costs). 

Negotiating with an unknown third lienholder to buy out their lien offers flexibility, while letting the property go into foreclosure results in the loss of your investment.

I got a new guy who wants to condition every inch of my project including seismic and EIRs for some unknown reason (single story, not taller than 12 ft).

See when a buyer is an unknown entity without a track record of performing they are an UNKNOWN RISK.Brokers get paid when properties close.

It's just dead money at that point.And the third piece here is that there are some legal precedents (depending on your state) where if you don't remove the current tenants from the property then they can continue to claim domain on the property for an unknown period of time. 

Most contractors will bid high to compensate for the unknown.