Our mistake was hiring a service to perform this search and the results were an obviously inadequate and incomplete report. 

Most people use BP forums to fill that role, and I think that's great, but finding someone you know who you can talk to and trust on a regular basis is better.But just so you don't feel cheated by my post, here are my (totally inadequate) answers to your questions.What do you guys recommend is the best way to buy an apartment building ?

Pg. 4 of the Tenant Survival Guide: "No matter what type of lease you have—written or oral, month to month or annual—your landlord cannot evict you without a legally valid reason.

I’d consider speaking with some or all of these.

I believe that a BRRRR would be best to try and reclaim some or all of the heloc $.

PROFESSIONAL INSPECTIONS AND INSPECTION NOTICES: Buyer may conduct at Buyer’s expense (unless payment for such expense is otherwise required by governmental regulation) any or all of the following inspections of the Real Estate by one or more licensed or certified inspection services: home, radon, environmental, lead-based paint, lead-based paint hazards or wood-destroying insect infestation, or any other inspections desired by Buyer in the exercise of reasonable due diligence.

The only "catch" is your employer is not paying half or all of it for you.

You can also fill the site and have a portion or all of the site removed from the floodplain by applying for a Letter of Map Revision based on fill (LOMR-F).

It then automatically generates ledger, cash flow, p&l statement that can be viewed by unit, property or all together.

Just not renting it is inadequate.