Okay the guy is chained when Visser three is feeding. Big whoop! Alloran could just morph something small, wait around for 2 hours rendering his body useless. Or better yet, just morph one of the giant creatures Visser three acquired. Seriously, this makes no sense. What's the worst they'll do to him if he tries? Kill him? That'd work to his advantage! Furthermore, if the other Yeerks are so power hungry, why don't they infest Alloran when Visser three is out of his body then kill Visser three. Considering how the Yeerk society functions, that might be an okay move.