Brokers have their place in the industry as do retail banks/mortgage bankers.

Best places to look for a HELOC are often the small community banks and credit unions close to the property.  

I use Buildium for tracking rent, fees, leases, and collecting online payments, but I don't use their reports for much, as I end up copying my online banking each year into spreadsheets.I've been using Rental Hero for the last hour and already impressed with it.

(no banks involved)2.

Many banks wont touch deals that are sub 90% occupancy, so you could negotiate short term seller financing to help give you runway to make the building bankable for a refinance while you reposition it.

The moment the first payout hits your bank account, all that goes away.

In response to your original question, closing agents should handle private loans just like a bank loan. 

You technically CAN break it up on Schedule E; however, it is not the best thing to do for audit purposes or an actual breakdown.You should have an operating/partnership agreement together and you should have a dedicated bank account for the property.  

You will need the cash to build it and I doubt banks will be favorable with lending terms.

Did you try a local CU or bank for a construction to permanent loan?