i would skip the tour. we did the tours last year and your too rushed in my opinion. not worth the money. you can get to baby beach and the natural bridge in the toyota with no problem. buy yourself a map (http://caribmart.com/arubamapbybb.html) thats the best one and go explore on your own. i think its more fun and you'll see more.
on thing you need to see is the natural pool. that is cool. the toyopta isn't gonna make it back there though.
i'd probably skip the depalm island. just don't see what could be worth that money. plus once there your kinda trapped there. this would be cheaper and the reef is just increible to snorkel on.. http://www.tranquiloaruba.com/