I would add some other questions that are not directly related to pinball and open-ended. For example, "what do you do when you are not playing pinball?" Or "do you have any other passions besides pinball?"
Or ask some tough questions. "Was there ever any time were you felt that you were wasting your time playing pinball and it was all a frivolous self-indulgence?" Or "did you ever feel that you were never going to be any good at this game and, if so, how did you deal with that?"
Or "did you ever feel that playing pinball at such intensity has made you miss out on other things?"
I'm sure that there are many more questions along these lines. The point is to get people to open up and tell something about themselves they don't mind telling and isn't about pinball. I already know that Bowen is a superb player, has won three world championships, blah, blah. But I don't know Bowen, not even one little bit, outside his pinball persona.
If you want to make it interesting, try to get at those other aspects of players' personalities. I bet it would be insightful, entertaining, and break up the monotony of the laser-beam focus of "pinball, pinball, pinball…"
And there would be no pressure on players either. They can divulge as little or as much as they deem appropriate. Some will say lots, some will say little. But I bet all of it will help to make for a better viewer experience.