It should be noted that each individual mission will only consist of some of the members of the team. Thus, players will have incentive to win because only those members will get money, increasing the chances that they'll win a gadget in the auction.
Examples of gadgets in the auction: bonus points towards the quiz (thus increasing a player's chance to stay), the ability to assign teams for missions next round, the chance to win an exemption. And more ^_^.
The Moles will not know who each other are throughout the entire game and will not partake in the quiz. Their objective is to focus on their own scoring and it is not to identify the other Mole. The Mole's will not know their scores from the quiz nor will they know the other Mole's score throughout the game.
I strongly believe the scoring aspect of The Mole's is balanced strong enough that they have incentive to secretly sabotage challenges without going-all-out and remaining hidden. Meanwhile, players have a dilemma on their hand, they can go for money and earn prizes that'll increase their survival. They can intentionally sabotage here or there, but if they overdo it they won't have a lot of money and their chances of elimination will be higher! I believe the rules will create a healthy balance of letting players invoke their own personal strategy and approach to the game, whether they're a Mole or a player ^_^.
The theme for the game will be a spy academy (think Kingsmen). I once read a book description about a spy academy where each agent was code-named as a playing card... when I began reading the book it didn't focus as much on the academy aspect as I had envisioned and think it'd make a cool theme. The players are new students to the academy training to becomes spies... whilst unbeknownst to the players, the Moles are elite students who are going through a test to see if they have what it takes to be a spy.