After 5 months we had a bad water leak under the house.

They usually sell for a really attractive price because investment property financing is (obviously) difficult, somewhat limiting the buyer pool to owner-operator small business owners (who in turn are typically great clients, as well).  

Amenities also drive demand to a rental and its much easier to have something like a pool if you are in a complex.

For example, the iconic Malibu waterfront homes were built directly over the water, many by variance, and assumedly will not be permitted to reconstruct, certainly not with the same materials or attached architecture.

I learned the hard way how to shut off water and how to winterize.

As for the first, yes we'd be able to do that (for example, replacing a water heater which is the mechanical that's closest to the end of its useful life).

First of all, let me pay my respects to the hardworking people in real estate and the treacherous waters they navigate—fronting hours of effort with only the chance of commissions and an abundance of non-forthright people out there.

I learned the hard way how to shut off water and how to winterize.

You could easily be $100k in for water/gas/power/sewer if you’re talking 4+ lots. 

To win the STR game, especially if you're a new entrant, the most important aspects are 1) Amenities2) Location3) Property type4) UniquenessAll are geared toward you standing out on Airbnb/VRBOHot tubs, fire pit, bowling alley, pools etc. or being in the best location in an area as well as being to host a large group are all things to help you win.