Getting permits after a variance depending on jurisdiction for multifamily for projects I have done has typically been 6-18 months.

Low cap rates because you dont have to do anything, just collect the 4% or 5% like a CD at the bank.10% Properties are going to be more involved.

A condo HOA can decide they want to replace all the roofs, but if the bank account is low, hit you with a $5,000 special assessment.

I recently started using Buildium and am realizing I now need to run both systems in parallel and unable to sink my bank account transactions on Buildium but Quickbooks is fine.  

Jonathan,Unlike credit cards with "Intro Rates", HELOCs are a standard banking product. 

That’s a pure cash flow play - monthly interest payments hitting your bank account is a great feeling!

Is there a bank or credit union that offer a loan for it?

The few lenders I've reached out to in my area (local banks, credit unions, etc.) are only working with primary residence for Helocs or Cash Out refi.

Private lender will wire ~80% to my business bank account shortly before close.

If you have a 12-month history of the property's performance, you may be able to get some wiggle room with more local banks for it.One thing that may impact the lender's ability to lend could be the Debt Service Coverage Ratio (DSCR), but as long as the property cash flows well then that shouldn't be an issue.