I did actually come up with a motive for Peter and promptly hoped Eastin had not also come up with it because I think it's a more interesting motive than anything I can come up with as Moz's motive. If Peter's the mastermind, then he was pressuring Kate for the cache because it pissed him off that after all Neal's schemes, the only thing he nailed him on was the security bonds, and he wanted evidence to get him for everything else. I don't think he magically tricked Neal into suggesting the work-release, I think he took that as an opportunity to work on Neal from the other side, and honestly the idea that Peter worked a long con on Neal for weeks and weeks while secretly being so bitter bothers me some. I still think Moz is the better set-up, but I find opportunistically-working mastermind Peter possible.