As a US citizen I have an SSN, file taxes every year on my foreign employment income, hold US-domiciled assets (stocks, IRA, 401k), and I have a ~15 year credit history with a decently high score.

Low insurance" is concerning to me, as Athens gets a LOT of high wind / weather / tornado activity for unknown reasons - they just got hit again last weekend. 

We bought the stair tops from Lowes and had them delivered to our house.

Can anyone shed some light on what kind of down payment, terms and qualification requirements we would typically be looking at for an SBA or low down commercial loan?

When revenue is low in the first couple of year, so is the interest payment.  

This deal is a multi unit building that has low rents, but doesn't really need any repairs. 

Low value markets might be Pennies on the dollar like you allude to. 

The denominator in the calculation is your capital/equity and with no debt the return on your existing equity is low.

Moreover, I would recommend prioritizing a W2 position over 1099 self-employment/sales for two reasons.

They use leverage in some of their funds, which can increase returns, especially if they have a low cost of capital (but potentially increase risk and trigger UBIT issues).