If was a fun and beneficial exercise to try. 

Well they’re just exercising their right so, I’d transfer it back and let that be the end of it.

Buyers are often sucked in by a 7 cap STNL only to find out tenant is local and debt rate is higher negating the extra cash flow they thought they would be getting.Now on certain medical NNN or say industrial occasionally you can hit an 8 cap for really larger properties 10 million and above.If something is in the lower price range and an 8 cap usually something is going on with it such as business downgrade or fixing to file BK etc.Developers are not going to build for a 9 cap rate to cost and sell for a 7.5 cap because YOU want a deal.

(Medical conditions is not something i screened for)But thats all water under the bridge nowI have found that in florida there is no requirement to disclose mold remediation to tenants.  

In regards to the financing and the transfers - there is always a potential the lender can exercise the Due on Sale Clause. 

I agree with what you said I’m currently working for a medical company, and just trying to build my credit.

The exercise of putting in costs and lifetimes to calculate projected maintenance/cap ex is a good exercise because it shows where a particular market fits with respect to the 50% rule. 

They've been there for 2 years and feel it's their "home".Did they decide not to exercise their option or are they simply unable? 

Most banks will exercise what is known as the Due on Sale Clause for this type of transfer, essentially stating you have 30 days to pay off the note in full or transfer the property back into your personal name.

My mom and aunt now want to move to AZ, for my aunt's medical benefit, and the house is in FL (3/2 1400 sq ft with an uncovered pool).