They bring all their own cleaning supplies and take my laundry offsite to wash themselves.  

This will supply a solid income stream.  

There are also 2 different types of fee structures - a split fee and a Host-only fee. 1.

To make extra sure it appraises high enough for the refinance, this would be after I talk to an inspector and get a few GCs to bid the job, might also get a structural engineer to come up with a repair plan for the GCs to look at when getting me bids.

The current incentive structure makes it very difficult for an assumable mortgage to actually be a tangible tool for buyers. 

I worked for a family owned company that built laminated timber structures throughout the Northeast but one of the sons had a good portfolio of multi family properties throughout Jacksonville and Orlando.

They're like bank & credit union loans... but with (i) more leverage, (ii) more interest only, (iii) [typically] lower rates, (iv) non-recourse structure, and (v) no deposit requirements / no requirement to start "a relationship". 

They rented the units to bad tenants, misallocated funds (including two months’ worth of rent), and prioritized unnecessary repairs while neglecting key structural issues.

You can also find a MTR consultant or someone who operates in the area to help you determine the rent rates, demand, and supply numbers in your market. 

My family is donating supplies for the flood.