Not so much where I am - most people cover up pretty well!
I think having your skin out in direct sun is hotter than a thin, loose, breathable layer in a light-coloured fabric, but perhaps that's personal preference!
Yes, and men choose, by and large in Britain, Australia, NZ, the US, Canada (and perhaps other places - so maybe most English-speaking nations?) to wear swim shorts and not thongs. I think that's interesting.
And no, I don't think that women necessarily dress for men as such, as individuals, but I do think that the trend of things such as high heels, heavy make-up, Botox, fillers, thong bikinis, scrunch bum leggings, very low cut tops etc are all evolving within a patriarchal culture that has a strong tendency to sexualise and objectify women, frequently seeing them as ornamental objects more than people.
To think you can live within that environment without being (subconsciously) influenced by it is a little naive.