The best way to see the Island is to get off the ship and get a mini-bus along with other passengers, usually around $15 per person you can go around the whole of the island, this is the best way as very informal and the local guide will stop at a local drinking whole if you ask him. Also you can get drinks at the Sulphur springs, please take a hanky with you for over your nose, It is a dreadful smell on approach, but not too bad, when you get used to it. Have fun, St Lucia to wonderful, don't forget the Duty Free shops on arrival in port, great value, and if the Market is on, have a look around, Locals are great and you can get some fantastic bargain.
Yes they are near, normally on the same tour. There are stores selling local bits, dinks and snacks. Also WC are availabl.