Maybe what doesn't make sense to me is (if all variables are equal) why you wouldn't install solar, get 12 months of financials to show the benefit, and resell it. 

HELOC from my primary home, which I initially leaned towards thanks to David Van Horn's opinion, with a 5.5% variable rate & I believe paid back over 3 years.

Complete waste of time in my opinion but there are a lot of variables unknown to me.

Granted there are many variables, but there could be a market for selling your property. 

When using hard money lenders you have a lot of variables; are they legit, if they are legit how many "points" do they charge, what interest rate, for what term, what are their "junk fees", do they actually fund, what is their policy if you can't pay off the loan at the specified date and so on.

depending on the LTV requested, your credit history, your real estate resume, and the desirability of the property being financed, you will pay a moderately higher interest rate to a much higher interest rate, with shorter term, more points and fees, and variable rate interest. 

Other than finding out about what percentage they refinance, the terms (fixed or variable rate, amortization), seasoning period, what other info would you suggest I find out?

Then I would calculate everything with financing, add in the variable expenses, and see if it still has acceptable returns.

@Scott Skinger When I lock a loan I consider quite a few variables, here are three:1.

I'm still analyzing whether this deal makes any sort of sense.I have more variables to mess with.