My kiddo may be interested in participating in a Build and Battle Pokemon event.  I obviously need to be in the room with him, but don't plan on participating in the event itself.  Do I still need to buy a $22 ticket?

I've participated in events where people just hung around and watched. As long as you're not being disruptive I don't see why it would be a problem.

It's in hall B, so there should be plenty of space to sit near by.