I agree with the other posters about conversations being essential and I definitely like conversations to flow, BuuUUuuut sometimes it is easier to have some questions in the back of my mind just incase we get to those *twiddling thumbs* moments.
Things I like to keep in the back of my mind to ask on a date are:
What are your goals and what motivates you?
What do you enjoy doing in your spare time?
Where do you see yourself in the next five years?
What are your turn offs in the opposite sex (not sexually...lol)?
What's the craziest thing you have ever done (answers to this could give you some red flags lol)?
Also there are some questions that if you ask could spark conversations, like asking about his family, his childhood, some of his favorite memories, etc.