What would be a suggested one week itinerary on the island?

Day One: Relax. Decompress. Forget about the real world. Take a lazy walk through town.
Day Two: Relax some more. Take a snorkel trip to Hol Chan and Shark-Sting Ray Alley (or go diving).
Day Three: Bike or cart to the North End. Walk the beach and have lunch at one of the North End beach hotels or have a seaside picnic.
Day Four: Take a day trip to Lamanai or Altun Ha ruins or to the Belize Zoo.
Day Five: Take a catamaran or other boat trip to Caye Caulker, or take a day trip to the Belize Zoo and Western Belize.
Day Six: Bike or cart to the south end of the island. Take a snorkel trip to Mexico Rocks (or go diving.)
Day Seven: Relax and start worrying again about going back the real world.