Yup definitely something missing. The show seems to be the bastard child of big brother and survivor.
They shouldn't be follow the leader. Make them have to earn their reward. I would love to see them have a fake treasure/dead ends where if you didnt get the clue right, you could end up really wasting your time. What fun would it be for them to get the clue wrong, spend their time digging up the treasure chest only to open it and find out they didn't win and they have to go back and figure out where they went wrong. Bet that would stop the follow the leader stuff, not to mention make it a brains and brawn challenge.
Down time: What makes reality shows fun are the personalities. I don't love any of these people, except maybe Rupert and he isn't enough to carry the show. There isn't a clear villian, where is Johnny Fairplay when you need him? The host isn't asking critical questions to stir the pot.
Why not make the pardon more dangerous? Say instead of just being safe from the vote, make it so if the captian black spots you, you get to swap places with one of the officers. So the captian gambles when he blackspots members of the crew and people are more interested in bidding on it becuase if they hold it and are blackspotted they now get to be an officer with the monetary advantages the position holds.