Provided a suitable down-size from our old home, with the ability to generate cash flow after we move out in a few years.

ROBS is designed to generate tax-sheltered income that you canNOT access for personal needs. 

My main goal is to build my real estate portfolio to generate enough passive income that I can quit my 9-5 and dedicate more time to RE investing.

They will not generate respectable revenue numbers for 99% of their listings.

Advertise it online (though this generates mostly spam for me.)  

% for 20 years.My payment would be much lower, say roughly $850, which will generate more monthly cash flow, but I'm adding 12 years of payments. 

Just to realistic expectations, you can probably generate up to about 20-25% cash-on-cash returns in good rental markets these days (I'm from Baltimore, but don't know the market very well anymore), so your $160K would realistically generate about $30-40K per year in pre-tax cash-flow.To earn more than that, you'd need to take a more active role and do some more risky investments.

I've done all the calculations and the property is going to cover the expenses and generate a decent amount of cashflow.

You will likely not be accepted, but you will at least get a computer-generated counter-offer form HUD that will tell you what their current minimum acceptable "net" is.

., a war in Europe, a CEO scandal or even a random tweet by an executive (like Elon Musk).