Unique pieces are great for "Flair" and individuating your property but if it fits in a suitcase and isn't fixed to the wall or floor then it will not be long for your STR.

Painting has started on the interior (Benjamin Moore - Smoke Embers in case you were curious), as has flooring and lighting.

Property includes: (2 buildings)The large old building with main level office previously a dental office and potential for build out second floor of (1)-1br efficiency apartment, (3)-2br/1bath.

If you are doing a paint, flooring, countertop, and some hardware fixes is you will not need permits.

We also didn't take into account the slant in the floor either. 

Strip the floor to the subfloor and paint over it to stain block then just recarpet or put in vinyl to mitigate future stains. 

Maybe a fresh coat of paint, flooring, unless what's there now if salvageable, make sure your electrical and plumbing  are in good working order.

I am leaning toward removal because the floor is run down, the risk of increased pests or feral cats, and there is already a storage closet off the patio.

I stopped at the "right" part.You need to start interviewing PMs in Austin, getting a feel for prices to renovate(hvac, water heater, floors for material + labor, etc.).

It has gas baseboard heat across 3 floors, with second and third floor being a combined unit 2, new furnaces installed two years ago.