And better yet 80%+ of this asset class tenants are home owners by nature, divorcee's in process, there living standards are home-owner conditioned. 

So you must cover that 10%, holding costs, and have reserves for overruns. 

I've included an example below to help illustrate this.So different lenders have different rates (which do vary even for DSCR loans) but these are factors they all consider.See example below:DSCR < 1Principal + Interest = $1,700Taxes = $350, Insurance = $100, Association Dues = $50Total PITIA = $2200Rent = $2000DSCR = Rent/PITIA = 2000/2200 = 0.91Since the DSCR is 0.91, we know the expenses are greater than the income of the property.DSCR >1Principal + Interest = $1,500Taxes = $250, Insurance = $100, Association Dues = $25Total PITIA = $1875 Rent = $2300DSCR = Rent/PITIA = 2300/1875 = 1.23If a purchase, you also generally need reserves / savings to show you have 3-6 month payments of PITIA (principal / interest (mortgage payment), property taxes and insurance and HOA (if applicable).

The property may not have any vacancies, but if it does, just make sure you have enough reserves to cover that. 

ONLY when I pushed further, did they actually release those dates (and I received an email with the subject: Your reservation XXX was cancelled at property YYY), and those dates showed as truly open across both calendars. 

Most importantly please be sure to keep money in reserve.

Depends who you ask and how secure you feel about your income On the one hand being debt free is great, but leverage allows us to build our wealth quicker.RE investors are notorious for being cash poor, so I would avoid thatIf youre able to comfortably save 100k a year and have enough reserves, I think buying leveraged properties is the best way to scale.You could kill two birds with one stone theoreticallyThey say paying an extra month a year towards principal saves you 7 years on a 30 year fixed mortgageUsing that logic you can add 2+ months a year on your primary, and buy 1 property a year and keep enough reserves. 

For any one person's situation, one approach may work better than another.For someone who has the cash flow, and has the equity but not the cash reserves, the HELoC can work, but is NOT the only choice.

Expenses: What are the operating expenses, including taxes, insurance, maintenance, and reserves?

I could, but the $$ fallout in lost reservations would probably be greater than any gains.