I suspect they might have been in poor shape, bought, renovated, and re-sold.

If you're considering moving into your dream home, I would like to speak to you about buying your existing residence......IMO, before I seek any business relationship with a client or customer, they need to be in a position to be a customer not a suspect but a prospect.Direct mail is fishing.

I suspect I will have one vacancy in a couple buildings I own over the next 6 months.  

However, given you're going to grad school I suspect you have other goals and I'd say don't underestimate the value of pursuing those goals as well.

I suspect that you will have to purchase a different property because this one has already been recorded.

I have a loan of a deceased that my brother is supposed to be paying (he is not very capable, so I suspect that I have made more payments on this loan than he has but I digress). 

In fact, I suspect that there are those purchasers who would prefer being the contractor's big fish in their little pond, even if it's only a few projects a year, than being a little fish in the contractor's big pond of projects.

I like to stay at hotels--BUT(I think) the Tax you are complaining about is a combined state and city tax that all hotels pay, not just AirBnB.It's called the Hotel Occupancy Tax and is paid by the customer.My understanding is they use 100% of the money to increase tourist travel to Texas-generating more stays.If some of your local competitors are not paying it (you really have no way of knowing if they do or not) they will eventually get caught.I imagine there are some businesses that a lot of this collected money gets steered to, and a handful of people living very well because of it--but they are bringing more customers to Texas.I suspect it will not go away, and is just a cost of doing business.https://comptroller.texas.gov/economy/fiscal-notes/2016/june-july/hotel-tax.php#:~:text=Under%20Texas%20law%2C%20local%20HOT,generating%20more%20hotel%20occupancy%20tax.

I also suspect that you might be breaking the law if you don't hold the deposit, as a deposit.

If you want financial compensation then you need to take them to Small Claims Court.If they are not a REALTOR, then your only recourse is to take them to court.I can't speak for a judge and don't know all the details, but I suspect it could be a waste of time.