It's tough to say exactly how many. But you can see the wide range of comic book conventions, fan clubs, and online discussions, which indicates a substantial number of people have an interest in comic books.
The number of people reading comic books varies a lot. It depends on factors like the popularity of specific comics, availability, and marketing. But they are definitely popular among many age groups and demographics.
The number of people working on comic books can range widely. For indie comics, maybe two or three. But for major comic publishers, it could be a dozen or more, including pencillers, inkers, letterers, and proofreaders.
It's hard to say for sure. But considering his creative style and love for diverse forms of entertainment, it's possible he has some interest in comic books.