Keep in mind we're only shown what the show wants to show us. Joe may have searched hard for that idol and just not found the clue. I agree that if he doesn't win immunity he'll be voted out. I like Joe, so I hope he keeps winning for as long as he can. I also like Jeremy and am glad he's made a nice little safety net for himself. If Joe can't win this game I'll be happy if Jeremy can.
I'm surprised that Abi has been so quiet for so many weeks. Has the bad weather washed the spitfire out of her? I believe that Stephen will soon find out that his move last night will not be looked kindly on by the rest of the tribe.
I'm pretty sure if Joe recruited his alliance to help find a hidden immunity idol, that would have been shown. And honestly, if any refused, it would have helped Joe know exactly where he is on the totem pole.
I don't know, maybe he is looking forward to the trip to the Ponderosa, as it will take a team effort to get him the million dollars.