I'd encourage you to explore simply selling the house and letting your parents take the tax free exemption. 

A couple questions I brought up was how can we protect it for them loosing to insurance companies or medical (nursing home) with declining health?

I then had a thought while talking to him, what if we used my LLC to hold assists for him, then there could be a tax exemption.

The office unit is currently 1700 sq ft of built out medical office space.  5 exam rooms, all with sinks and cabinets, two nursing stations, with sinks and cabinets, waiting room, administrative/check in area, large provider's office, large handicapped bathroom, handicapped ramp, plus a very large room with half bath on the second floor, that could be used as administrative space, or office space or staff break room. 

They function like medical properties.

How to set up and link a legal trust as a member to your SLLC so that the transfer of properties into your company is done smoothly and correctly without issues with lenders or banks, etc etc, same reason you don't DIY your own medical issues.

It is looking more and more like STRs will only be allowed in some commercial areas and in properties that are owner occupied with a homestead exemption in place.See articles below:https://nola.curbed.com/2018/5/25/17394232/new-orl...https://www.nola.com/politics/index.ssf/2018/07/sh...https://www.nola.com/politics/index.ssf/2018/10/sh...https://www.theadvocate.com/new_orleans/news/artic...https://www.nola.com/politics/index.ssf/2018/09/sh...https://www.theadvocate.com/new_orleans/news/artic...https://www.theadvocate.com/gambit/new_orleans/new...https://www.nola.gov/city-planning/major-studies-a...https://www.nola.gov/city-planning/major-studies-a...

The market for sure is not a Austin or dfw market but Tyler being a growing medical city, it seems to be growing well. 

I might make an exception on credit score if it's related to old medical expenses.

Most employment is govt, education or medical services for people on some form of entitlement.