Ok here is your touring plan with Sharks Underwater Grill included!
Get there are park opening (9:00am) and head to the right this time. While heading to the right you will pass the dolphin nursery. There is a newborn dolphin that I believe is still living with its mom in the nursery. So that would be something cool to check out. Continue into the waterfront area over to Seaport theater for the 9:30 showing of "Pets Ahoy." Pets Ahoy is a dog and cat show that is great for young kids. Its also got a few other unique animals in the show too. All the animals were adopted from local animal shelters.
The Pets Ahoy show is about 17 minutes long. Following the show, head over to the Shark encounter to make your reservations for the Sharks underwater Grill. The other half of the park where Shark encounter is located, doesn't open until 10:00am. And since Pets ahoy is 17 minues, it will only be around 9:50 when you exit the theater. You may have to stop and wait at a rope for a few minutes until 10:00. But make sure you near the front of that rope so you can head over to Shark encounter and make your reservations quickly before everyone else does! I believe you make reservations at a Kiosk located next to the shark feeding area. I apologize, I don't know if they give you a reservation time or if you get to pick a reservation time. But I would suggest a time around 2:00 if you get to choose your time. After you make your reservations, buy some shark food and feed the sharks in the area near the Kiosk. Or walk through the shark encounter if you have some extra time.
After making your reservations, continue down the path to Shamu Stadium for the 11:30 showing of One Ocean. I would suggest getting there 40-30 minutes before 11:30 to get the best seat. If you have some more time to kill, then hang out in Happy Harbor for a little while and ride the Shamu coaster. A new feature in the One Ocean show, is texting. Before the show starts, you can text you or your children's names to a number shown on a screen and you will see you and your children's names on screen before the show starts. You also have the ability to text in a picture of your family. The picture will be displayed at the end of the show on the screen.
Following the One Ocean show, head to the back of the stadium for more time at Happy Harbor or to begin your Halloween Spooktacular fun. Halloween Spooktacular is included with park admission and involves trick or treating, costumed characters, and other fun Halloween activities. Some of the Halloween activities cost extra, however trick or treating is free. The Halloween Spooktacular activities start in the Happy harbor area behind Shamu stadium and go all throughout the Bayside pathway behind the old ski stadium. The pathway continues all the way to the dolphin nursery where you began your day. So its pretty much a straight path from the back to the front of the park. The Spooktacular events should take you an hour or two so by this time it should be around 2:00. I think there is plenty to do that will take up almost two hours. When you reach the dolphin nursery, head over to Sharks underwater Grill for lunch.
Say you take about an hour and a half and Sharks Underwater Grill. That means it's about 3:30 at this time. Head over to the Pacific Point preserve area to feed the Sealions and on your way, stop through the Penguin encounter to see the Penguins. Right next to the Penguin encounter and Pacific point preserve, is the Sealion and Otter Stadium. Get there for the 4:45 showing of "Clyde And Seamore Take Pirate Island" Following the show, head over to the Key West at Seaworld for Dolphin and sting ray feedings. Dolphin feeding are only at specific times during the day and I'm not exactly sure what time in the afternoon feedings occur. However, you can still pet the dolphins no matter what time of day it is. Sting rays can be fed all day so that won't be a problem. Continue through the Key west at Seaworld area making stops to see the turtles and Flamingos. At this time it should be around 6:15-6:30.
If it's around 6:15, you have a few options. You will be back near the entrance to the park so you can leave for the day, or you can go back over to the waterfront area to the Seaport Theater where you saw Pets Ahoy earlier in the day. There will be a different show being performed at that theater at that time of the day. Its called "Countdown to Halloween" and features the characters from Sesame street. This too is obviously a great show for kids. The show starts at 6:30.
Following the show, you can again leave for the day or cross the bridge over to Shamu Stadium for the 7:15 showing of "Shamu Rocks" I don't remember if you saw Shamu Rocks on your last visit. But if not, its definitely worth the watch. Its my favorite show in the park. Its obviously different than One Ocean during the day. Something cool to keep in mind, is the Camera operators at the show do audience shots about 10 minutes before show time until Show time. They look for audience member who are dancing and having a good time. But during the Halloween season, they also look for young kids dressed in Halloween costumes dancing and having a good time. If your kids come in Halloween costumes, there is a good chance they may be put on the big screen while dancing for all to see. Following Shamu Rocks, there really isn't much more until park close at 8:00. So that would conclude your visit.
Here is info about sharks underwater grill including a menu:
http://seaworldparks.com/en/seaworld-orlando/Dine-and-Shop/Dining/Sharks-Underwater-Grill
Here is a show schedule for October 15th (It will take you to the current day schedule but just click the 15th on the calender):
http://seaworldparks.com/en/seaworld-orlando/Park-Info/Park-Hours
Any other questions, please feel free to ask! Have fun!