I would like to interrogate the pope. I would ask him, 'When you were the previous pope's enforcer - what was it, exactly, that you enforced?' (I know the answer to this question - a bit of googling should get you there)
I would also ask him to explain why he allows some catholics: filipinos for example, to believe that he speaks the word of god. This has led to situation where desperately poor people: that barely make a living crawling all over rubbish tips looking for scraps, have more and more children because the pope says that using contraception is a sin. Children are being born to families that live on the streets - they will grow up on the streets - and when some shopkeeper decides that the presence of these street urchins is bad for business he will shoot them and they will die on the streets.
Dawkins speaks for himself - both eloquently and eruditely - through his books and lectures. I would suggest that people read his stuff before attempting to engage him in converstion.