Sounding a little more conservative, I would take all the cash flow, add in about $1000 to $2000 (or whatever you can) and pay 1 of the mortgages off within 3 years.

It sounds like you are making this property an investment property so the FHA 203K would not be an answer because you are required to occupy the the home (a multi-family home is ok if you occupy one of the units). 

It sounds to me like you and your girlfriend might have opposing goals and that could lead to more problems down the line and I have a feeling could be a part of the struggle you’re having right now.

It sounds incredibly fishy.

It sounded like you would have enough to cover either loan type and that's why I wanted to bring up the conventional option.Keep in mind under both options you will need to be a mini-project manager. 

I know 10 years sounds like a long time but it's really not. 

BTW, 4-Plex sound like wrestling move,, :--)

That means in the end, it will take you 12 months...1 year...to recover the negative CF from that vacant month.Does that sound like a good deal?

Sounds about right with the recent interest rate increase. 

Also it sounds like you have two tenants leaving so your total rent right now could be as low as $525/mo until those others are filled.Mortgage is given as $1200/mo but is that PITI?