I am local and could even view in person to get a real time experience if you like. 

Next day another person calls in, just repeating what I said the day before in a dumb way and eventually said, you know you have to refinance the 1st mortgage, right?

At least that way I can use some of the cash flow to save for a personal residence.Any advice/perspectives on how I should approach this?

I'm not sure of the legality so I can't comment there....either way though I'd just go get a personal loan for a balance that low or transfer the property sub-to...

As in two or three years living with this person whose shall we say lifestyle is so uncomfortable to you???

Personally, I would do the research first, get all the answers confirmed and then look into the market to do a deal.  

A true DSCR product doesn’t care about your personal debt. 

If one person stops paying and it's tolerated, It's more likely to spread within the house.

@Joseph MuleroTo boost your rent plan and make more money in the medium-length rent market, think about these steps: slowly add furniture to the new place while you stay in your current home, pick cheap furniture, use a credit card with good terms, look into loan options like personal loans or home equity credit lines, try out the market by listing the place with few furniture pieces, aim for easy-to-change furniture for flexibility, and talk to pros like real estate agents or home decorators.

I personally don’t want to use FHA.