I’m in an east coast beach area where it’s been traditional for guests to bring everything - linens,TP, paper towels, dish soap, cleaning supplies etc.

Its a central point between Atlanta and Knoxville, Atlanta and Nashville, Within a 5-7 hr drive to a handful of coastal beaches, and a great place to open a place of residency for someone. 

It is typically closer to the beach, but further from DTSP.Let me know if you have any other questions!

I live in the Tampa Florida area and we have Airbnb/STRs all over the county and not just on the beach. 

I live in the heart of the big boom area, Palm Beach - Miami, crazy high numbers 

Can you 1031 a duplex (long term rental currently) or multiple duplexes to invest in a beach front property and use it as a short term rental?

There are no laws, rules or regulations preventing any foreigner, American or otherwise, to buy property in CDMX or Mexico for that matter.If, by having success, you mean getting a profitable investment, I'm sure many American and other investors got that over the last few years (I personally haven't since I've focused my efforts on Mexico's beach markets, which are far better in my opinion.

It has a ton of pools and is walking distance of several other locations on the beach.

On a different thought (not based on any development) is imperial beach.

Ironically, in line with your interest in Galveston, I am about halfway through constructing a beach home there (Beachside Village), which I plan to use as an STR / vacation rental.