. $30K should be more than enough for fresh paint and flooring and some other odds and ends, but if you need dry wall, cabinets, countertops, mechanicals etc it could get much pricier. 

4- of course we'd want to verify it's permitted use per zoning5- Capex will need to be budgeted for a reserve account for tax purposes6- need to get the stage 1 and 2. 7- by subcontractor issues do you mean a mechanics lean on the property?

2) Are Vendor Mechanic's Liens extinguished at tax sale? 

Gritty students succeed, and failure strengthens grit like no other crucible.”― Jessica Lahey

Rather than take a complete loss on the uncollectable debt, can I take the assigned debt, make collection efforts and upon failure to collect declare the loss to offset the capital gains?

Closeups of all mechanicals (hot water heater, furnace, etc.)

The mechanics of it.  

Of course, as is always the case, a lien will not be divested if the lien holder has not been given proper notice of the sheriff sale - so even a “free and clear” can have an encumbrance when a failure to properly serve notice happens.Hopefully that was sufficiently clear; if not, post more questions and I’ll do my best to offer clarification. 

You need success and failure metrics or baselines on these reports.Example.  

The piers are just placed there with no mechanical anchorage or attachements to the house framing.