Our keynote speaker last year was one of the founders of Nvidia, and, yes the animation went over well. 
Excellent rules.
On questions, I’ve noted that maybe ten people out of five hundred ask 25% of the questions. (I’m one of them.) Anyone else notice this?
We try to get someone primed to ask a question, if no one else does. I’ve seen some conferences request the speaker produce some, but these are usually so detailed that it is obvious they are a plant. Usually the session chair asks one if no one else does, but unless he or she is really involved, they don’t inspire follow ups. I usually try to get the session moderator (the PC member responsible for the session) to ask one from the back of the room as a more credible shill.