I agree that going two days back to back would be a little much.
What you can do, is visit SWF early your first day, arriving at 08:30am. Do JTA and Kraken first, and tour the park.
A few days later, come back in the afternoon at 3pm, visit the Key West area where they feed dolphins. View a few shows, drink a few beers, eat dinner, then go see the last Shamu show of the night, which is called Shamu Rocks. It's more fast paced and much different than the day time show.