I would be far more interested in how to build a successful business. Everyone asks Elon about his big ideas, but how do you turn those big ideas into reality, specifically? I have never seen anyone ask him those questions. I thoroughly enjoyed the interview with Jessica Livingston because that was the primary topic. A missed opportunity in my opinion. I hope the rest of the interviews are more about the nuts and bolts of how to build a successful business.
EDIT
Ask him about the early days at PayPal. What are the lessons he learned that he applied to Tesla and SpaceX? What worked for PayPal but not the other companies and why?
The way I see it PayPal essentially helped an established incumbent monopoly (US credit card companies) with issues at the time maintain and extend its global relevance, lock down domination of cross-border consumer payments, meaningfully extend US intelligence sector surveillance, and continue to fuck the little guy. Only Europe and China are building a resistance now, 15 years later. That you have 5 or 10 rich people coming out of that little cash-cow who feel like publicly playing god with humanity's future or that they deserve some kind of respect for the 'achievement' is pathetic. Any number of people could have built that better, or with morals. If they had any sense they'd be ashamed at what they've done, and how it has seemingly irrevocably crumbled in to bigcorp screw-the-customer service mode. Besides, we all know the real e-vehicle revolution has already happened, right here in China.