Here's a thought on (part of) what Ben's up to.... he set everything up to get back at Juliette for trying to kill him (using Jack). I was no accident that Tom told Locke to go to Ben's tent when he did. And it was no accident that Ben was listening to the tape as Locke walked up. Even showed Locke where he could find it. Then told him their plans BEFORE the "initiation ceremony".