More and more states are requiring a form exempting from collecting % as a withholding. 

Dodd Frank will apply...see below.Not More Than 3 Properties Exemption Any person or entity cannot provide seller financing to an owner occupant more than 3 times in a 12 month period without using a MLO (mortgage loan originator).

These typically are the largest users of travel medical professionals.

Since I’m buying a new primary home, would I lose that tax exemption?

San Francisco has a number of hospitals for travel nurses and other medical workers and probably corporate professionals who travel there.

I believe Airbnb's policy said hotel's were exempt.  

Due to medical reasons a couple came to me looking to sell their house at a discount.

I work for The Realty Medics, a property management company here in Orlando. 

This is not a problem if you use a licensed CA real estate broker to originate your loan since they get an exemption against usury for loans secured by real estate.My strong suggestion is to find an experienced hard money lender at a local real estate club to originate the loan for your lender.

I will still make no exceptions for evictions on a record, no matter how other criteria works out, but a divorce, medical bills, student loans, etc., are worth questioning before rejecting.