You're treading in RESPA-infested waters there and these are federal, not state regulations.Referral fees for ANY closing services on residential loans are strictly prohibited under RESPA regulations. 

Places like Dallas and Plano many not have strict regulations yet, but seems like the community is firmly against STR, so that's probably not the side you want to be on.   

With everything exposed, were talking code requirements on everything.

Check the codes in your location for the minimum requirements for a home to be used for assisted living.

Recently after over a year of succesful payments a tenant payment was reversed for insufficient funds, according to buildiums (R01) return code, but they are certain the funds were available.

You could buy a house with siding made of corn cobs if you'd like and they'd finance that (assuming the corn cob siding passed code).The issue is that true log cabins tend to significantly limit buyer pools because they are a bit of a niche product so lenders don't want to finance them at all due to the added risk for resale. 

I use it for all of my out of state investorshttps://www.areavibes.com/It gives you a total LIVABILITY score for each street and zip code.

Be sure to check your zoning code to determine what kinds of businesses are allowable. 

#1 This website is a great reference point for figuring out what each area is like. https://www.areavibes.com/It gives you a total LIVABILITY score for each street and zip code. 

You'll likely see variation (even within a zip code) based on condition even though all might be 3 bedroom 1 bath homes (as an example).