Yes, I have been to St. Thomas many times, as a matter of fact my husband was born in St.Thomas, and grew up there. We are planning a trip there in December my In-Laws 50th wedding anniversary celebration, and we are looking forward to going.
(a) If you rent a car, be prepared to drive on the opposite side of the road, and I would greatly recommend you renting a car especially with the children, because the public transportation takes too long, and you will have more time to enjoy the sceneries, than having to rush to catch the public transportation.
(b) If you have bought into a tour the hotel transportation may help you.
(c) Scenic places - Meagan's bay - very beautiful, our children would spend hours there, Coral World, Drake's seat, Mountaintop, go to the eastside of the island to see St.John's, or you can take the ferry to St.John's and spend the day. You can also take the ferry to Virgin Gorda, but make sure you have your US Passports, there is also blackbeard castle, or blue beard castle.
(d) Caution - avoid been in places that you are not familiar with late at night.
It's beautiful in St. Thomas,a bit conjested,very hot, and humid, make sure you have lots of suntan lotion,and hats. The food is delicious, and the people are very friendly, but of course just like any place you want to keep an eye on your children at all times, safe guard your belongings, be aware of your surroundings, and try and get most of your directions from the hotel staff, if you do not have a map, but a map is also very helpful.
It's wonderful, it's beautiful, it's exciting, enjoy, try some johnny cakes, saltfish/codfish, coconut tarts, and fresh passion fruit juice.
Denise