Regarding Barbados, St Lucia and Antigua there are a lot of different beaches if you want beaches. But a private island tour with your own taxi would be a good choice.
St Maarten, depends on what you want to do. Beaches, watch the planes, zip lines, etc. Orient will be crowded if there are ships in, that is the way it is. Mullet is a nice beach but can get crowded. There are a couple of options if you want clothing optional.
St Croix, been a long time since we have been there -- but we did a taxi to a hotel and used their beach and had lunch.
