Wow what a great itinerary! I just returned from a cruise that visited Aruba and I would suggest this be the order of your day: Hire a taxi or local tour company at the pier to take you for a short (2-3hours) tour of the island visiting the windward side and the Natural Bridge and have them drop you off at the Havana Beach Club (about 1/2 mile south of the port) and plop yourself there for a great afternoon. They have a bar, restaurant, pool and small beach area with lounge chairs and there is no cover. It is pretty much of a local establishment, but in my opinion, much better than the overrated Eagle and Palm beach hotel area. When you have had enough of the sun, it is an easy walk back to the ship. If your ship is in port late, shower, change and head back out to some shopping/bar-hopping in downtown Oranjestad where there is a limitless and very happening bar scene. The information on our Aruba Port reviews site has just been updated: www.caribbeanportreviews.com/aruba.htm
And if you are interested in learning how not to see Aruba, you might want to check out the mega-review of the Brilliance of the Seas I just posted:
I would do my snorkeling in St. Thomas and save the parasailing for Orient Beach in St. Maarten.