Thanks guys. If you think the stock piece will hold up, then it will hold up. I don't expect to take any direct hits to the hilt itself. My brother and I often "duel" with hasbro sabers and we get pretty into it and haven't broken anything so, like I said earlier, if the blade extends at least an inch past the retention screw into the hilt, then there should be enough support there so the silver exposed piece isn't taking the stress of the blade. Am I right?
An afterthought: Can that metal blade holder be added after a mail-in conversion? i.e. if the plastic does crack inside, can it be used as a direct replacement?