I think just tell them that you need to use the laundry before they sign a lease is perfectly reasonable.

If you are both working, committed adults then it seems perfectly reasonable for her to pay her portion of rent and living expenses.

The house wasn't perfect; it had a small yard and was farther from city center but everything else was so pretty!

might be a perfect candidate for some sort of short plat. 

Especially when you start to rent out the units, you'll have a hard time choosing tenants as you look for the perfect one, etc.

It kills me to see what landlords get away with.

If it’s in an area going up in value, that you enjoy, I say it “counts” in your investing goals, even if it’s not a perfect house hack duplex deal, you took courage and bought SOMETHING and refused to rent the rest of your life.  

In a perfect world (which could happen), lets say we get the borrower to make 12 consecutive payments at $204/month with his loan balance being $14,000.

You should be able to get away with 3.5-5% down if you can live in one of the units for at least 6-12 months (or whatever they require now).

I don't work at a small regional bank and don't know all the details, but something about a) small bank with only a few branches and b) limited geographical footprint makes them get away with c) ignoring all the post-2008 Dodd-Frank type rules about income and "ability to repay" and needing to document that income and ATR.