If the one spouse has a consistent history of late payments to utilities and such, then I'd be more hesitant.

Based on my formula (8.3% vacancy, 10% repair, 5% CapEx, 10% prop mgmt, plus mortgage/prop tax/insurance and utilizes), I came up with $400+ in monthly cashflow and ~8% CoC ROI.

Smart thermostat or programmable is always a good idea for energy savings (more important if you are including utilities).

Tenants who pay utilities themselves might appreciate the fan to cut back on cost of having AC running. 

Maybe keeping the current mortgage and utilizing the $25,000 HELOC is a reasonable path...just a little slower than the "cash out refi and buy 2 more properties" path... 

Holding the land until utilities and septic become available before building.

We furnished the basement and rented it through Airbnb - the income fully covered our mortgage and utilities!

The house has a walk-out basement with 1 bed 1 bath and a full living area.We furnished the basement and rented it through Airbnb - the income fully covered our mortgage and utilities!

There is no wrong way to go about it, you can use OPM or "other people's money" or utilize a government downpayment resource or look into FHA loans to see if you qualify.For a first step get in contact with a mortgage broker to see where you and your financials stand as far as obtaining leverage on your money. 

I used the deposit to pay for the cleaning and anything left was applied towards unpaid rent or utilities.