That's a good defense of Castiel--I certainly agree with you that he never intended to expose Jimmy's family to harm. I think my frustration is a little more bigger picture, though; I feel like at the very least Castiel should have hedged his promises, and more than that I think he might have clued Jimmy into the length of the commitment he was making, if it really could be a thousand years.

Of course, it is also possible that Castiel really believed he would only need to be inhabiting Jimmy for a short time, and it was something related to his most recent trip to heaven that makes it necessary to hold on to Jimmy for so long, in which case I will withdraw the criticism.