What was the point of having Griphook's help if they weren't going to ask him about the bank's defenses? Of course, I also have this suspicion that if they hadn't planned to betray Griphook, he might have been more helpful and not betrayed them. We might not have a good idea of what wizards are capable of, but what other magical creatures are capable of is a complete mystery. He might well have known their deal was a fraud from the start.

And you're so right about the stupidity of stealing something you're just going to destroy...with the item that could be used to destroy it. *headdesk*

(Mmm...must go watch Sneakers now. ^_^)