We deliver our properties free of both (noted as such in the lease) and then contractually make the tenant liable for prevention/termination. 

In other words, I already have a checking and savings with BoA, but I would create a 2nd savings account (within my regular account) and put all the rental properties last months and security into that account (combined).Is this the correct way to prevent co-mingling of funds, or what would you recommend?

This would obviously reduce my cash flow on both properties, as I would be paying the minimum HELOC payment plus extra towards the principal to pay it off quickly.

Quote from @John Underwood: LOLI'm certain they will add restrictions to prevent people from doing this.

Send me a message if you would like a copy of our7 CRITICAL STEPS TO PREVENT A TENANT NIGHTMARE BEFORE HANDING OVER THE KEYS

Quote from @Makan A Tabrizi: Quote from @Marcus Auerbach: We try to get ahead of the issue by preventing it in the first place.

Its this sharp depreciating component which has always prevented such a purchase.  

The down fall is a Heloc can "Never" be used as an asset or for PITI reserves required when buying a new Primary or investment property.A heloc can also cause major issues with credit and one slight hiccup or missed payment the bank or lender who is holding the Heloc can close or reduce your line of credit.

Ok, if it's still sounding do-able, the next issue is that section 179 can't be used to create a business loss, so it would only reduce your taxes for the year if your rentals are operating as a taxable gain (but rentals are often at a tax loss thanks to depreciation).  

And this low demand could be a couple of factors, either a rural location with low population density or the area incomes are not high enough in order to prevent a rent burdened scenario.