SXM -As most have said, a different animal. Simpson Bay has lots of bars & restaurants even on French side (back side of Marigot) but I would not swim in that water - more of a dinghy freeway to all your choices.
Just remembered - Orient Beach just north of Oyster Pond on the windward (east side)..........lots of beach bars/shacks, water is a little bumpy sometimes but you don't see boats anchored off the beach.......
there is a clothing optional attitude especially in one sections for an all over tan.........iL Pinel nearby is nice setting with a small anchorage
St Maarten/St Martin Beaches: Orient Bay, the famous clothing optional beach
Agree with Z on the rest of SXM.
Anguilla - I actually liked it a lot when I was there in '05. We only paid for entry because we stayed in road bay used our dinghy to visit other spots. It gets much more expensive if you have to buy cruising & marine park permits for other anchorages.
Plenty of bars & restaurants along the beach.......and yes, you can swim in this water. It's mellow & a great island vibe.
Anguilla Beaches: Road Bay | anguilla-guide.info
We just did St. Barths = great place to visit but did not see any beach bars like Jost BVI. We also did Nevis, St. Kitts, Statia & iL Fourchue
I'll comment on Saba only that it was on voyage plan but Moorings had 100% restriction on it........you could sign an insurance waiver = no coverage but we passed & just spent more time at other places.
Statia was very rolly & the chance of Saba being vey rolly depending on conditions would be very high.
Don't worry too much - it will be fun
You did not say how long you were going for but SXM - ANG - St. B will give you plenty of oppt for all your activities.