Kerry should turn questions into statements and use the restriction on questions as a chance to show that Bush is a coward.
Example of a possible rhetorical strategy:
Question: What do you think about terrorism?
Kerry: I think x, y and z. The debate rules prohibit me from asking the President about x, because he was so afraid of the idea of me asking me questions, but I hope one of you reporters asks him about that. After all, he did (some stupid Bush action).
By the way, despite what the radical smear machine wants you to believe, I served in Vietnam and was shot at. With bullets. Questions don't scare me.
Update: Sorry, found the debate rules memorandum on the Kerry Web site and had to alter my poll.