As a life long San Diegan and Sea World AP holder, I don't think that there is any secret stuff or little tidbits for Sea World San Diego. It has changed so much over the years since I was kid and continues to do so today (we are getting two new coasters soon). Get there early to take advantage of the cooler temperatures and more lively animals in the exterior habitats. Check the daily schedule to see when some of the animals are going to be fed; that is fun to watch. Consider purchasing an interactive experience (before they monetized these, if you were in the right place at the right time, you could be invited into the "backstage" area of an exhibit to see an animal up close...we did this with the otters once and it was awesome).
If there is one recommendation that I could give you it is to be wary of the food. For some reason the quality of the food overall is less than satisfying in my opinion. The best food is offered at the up-charged dine with Shamu experience. If you are willing to pay for it, then I recommend it highly, otherwise the rest of the park food is meh. When the Seven Seas Food & Wine Festival is going on (like right now), they offer some really great food and drink options, but for the most part it really is mediocre at best. I have said many times to friends and family while in the park that the wonderful smells from their many open grills is heavenly, but very misleading...while the smoky vapors lure you in, the quality of the food finally given to you is less than satisfying. If you get there early and want to head out of the park for dinner that evening, I very highly recommend hitting the nearby Phil's BBQ. It is a San Diego gem!