OR refi one at 70% and get the 45k loan leaving some debt on the line of credit but keeping home 3 free and clear and adding a lot of value to it as well as getting some really good rental income from it.

I removed the chimney and added modern HVAC, making it the only house on the block with it, significantly enhancing its value.

However, if you've picked up on signs of potentially problematic behavior during your interactions, you might be able to highlight them by adding “good tenant conduct” to your list of standards. 

Quote from @Tim Horning: Hi Carl, I am going thru the exact same issue with my first rental; a large 3 unit house.

I removed the chimney and added modern HVAC, making it the only house on the block with it, significantly enhancing its value.

And if all houses have not been fully rehabbed (we do fulls on every buy), some expected number for capital expenses should be included in that (IE if you have 3 years left on your roof you need to be deducting $X from that figure, repeat ad nauseum for all major capex).

They’re built for heavy use and have faster drying times—usually 30–45 minutes—without needing major electrical changes.If you’re up for a bigger investment, adding extra stackable units in the garage could be a great long-term fix, though it’ll mean some electrical work and setting up proper ventilation.I’d probably go for the commercial upgrade in your current space first—it’s quicker and might solve the bottleneck right away.

Simply look at any large apartment building.

Below that is a parlor floor, which has the highest ceiling in the building and this floor is connected to the ground floor via an interior staircase which we added doors to both ends to break up the lower duplex into two separate living areas.  

If there is a specific document you would like to see added next please comment in this thread so I can get it added to the list!