I made that map, and I'm not American. You can google "population density map Mallorca" and compare. I had the same assumption as you, so I googled it before publishing.
I used to go through a very similar process while booking longer stays for remote work trips. Now it gets even more complex as I have a baby, what means more parameters to consider.
Curating Airbnb listings ideal for work (desk, office chair, good internet) in interesting travel destination can be actually a good MVP. Something like crowdsourced (and cheaper) version of https://wander.com/
If you sell digital products (SaaS, ebooks, etc.) by USA based company to EU clients, you have to apply VAT of EU country where the client is based (Belgium 21%, Hungary 27%, Ireland 23%, etc).