A few other ideas for you where you can have a 1 credit TS and then watch fireworks (though not from the restaurant):
1. Kona Cafe earlier and then head out to the beach at the poly to watch
2. Chef Mickeys or the Wave and then head out to the 4th floor viewing patio at the CR
3. 1900 Park Fare or Grand Floridian Cafe and then watch from the boat dock at the GF.
You'll need to check the fireworks time and leave yourself plenty of time.