Regarding Dominica it is worth renting a car in Portsmouth and driving to Roseau, then Trafalgar Falls, then on the windward side of the island as there are several stops there and finally back to Portsmouth. The roads are OK and it beats taking a tour bus, especially since those start in Roseau. Another option is to talk to your boat-boy from PAYS and he'll recommend a tour guide for a personalized small-bus tour (4-8 people max). I've done that as well with good results.
The Saintes are wonderful, the first stop from Antigua for clearing into Guadeloupe is the quaint little village of Deshaies. The anchoring can be tough there, unless you get in close you will anchor in 40-50 feet with mediocre holding. Île Pigeon is the marine park, but it is only worth stopping there if you dive - in which case it is wonderful with an underwater bust of Jacques Cousteau (who said it was his favorite place to dive).

The other recommendations are in the other thread you posted on the same subject.