I agree....Blue Horizons, Clyde & Seamore, and Pets Ahoy are all don't-miss shows for our family. Be sure to go to Clyde & Seamore early to enjoy the antics of the mime. His part of the pre-show is as funny as the C&S show itself.
Quick Queue, which gives you unlimited front-of-the-line access to all rides, is available for purchase if you want it. I would wait until you see how busy the park is before buying. Its MUCH better than the Disney Fastpass system as its not time restricted, valid all day, offers unlimited use, and applies to all major rides in the park (except the swans and those in Happy Harbour).
Your whole group should be able to do Turtle Trek, the Skytower, Antarctica, and maybe Journey to Atlantis (if the 4 y.o. is not afraid of the big drop). If there are any coaster lovers in the family, be sure to plan on riding Manta. My DH and DS rave about that coaster, which gives a very unique ride in comparison to standard roller coasters.
Our favourite restaurants are Voyageurs (for BBQ) and SeaFire Inn (fettuccini alfredo, fish & chips, etc.). We like Mango Joes for lunch/quick service. The only restaurant I would say to avoid is the Terrance Garden Buffet (pizza, pasta). The food there is "fine" but nothing spectacular. There are better places to eat in the park.
You may want to consider the all-day dining plan if you are planning a full open-to-close day at the park. Even breakfast is included on the plan. Its truly unlimited so you can eat and drink all day for one price. You can check out the pricing details here:
http://seaworldparks.com/en/seaworld-orlando/Dine-and-Shop/Dining/All-Day-Dining-Deal
If you are looking for something kind of special to do, the Behind the Scenes tour is running at buy one, get one free for the month of January. Regular price is $29 pp:
http://seaworldparks.com/en/seaworl...usive-Park-Experiences/Behind-the-Scenes-Tour
Also, if you think you might want to purchase a photo from your day at the park, you can pre-buy a voucher for a half-price 6 x 8 photo:
http://seaworldparks.com/en/seaworld-orlando/Dine-and-Shop/Shopping/Photo-Offer