On St. Thomas itself I've stayed at Pavilions and Pools. They have a couple dozen condos each with its own private swimming pool. The pool itself is only about twice the size of a plunge pool, but it is 100% free of tsniut issues
The free breakfast has lots of kosher. No other frills there, just relaxation and complete privacy. Recommended if that's what you're after.
There are touristy things to do in addition to water activities, mostly where the cruise ships dock. The only one I did was take a chair lift up a mountain for hiking, nice views, and a parrot show. There was also a great outdoor market that I went to more than once.
Where I spent most of my time was on St John though, driving through the national park and hiking to parts with no roads. There is awesome snorkeling on this island and usually no one else around (due to remoteness). There is a great Westin property on the West coast (facing St. Thomas). Once you drive 5 minutes away from that coast, the number of people you see drops to nearly 0. The beaches are not that special on either island compared to other places in the Caribbean, but they are still great.