"Here is how you get started in LARPing" on a practical level. I'd really love to see Arisia offer a step-by-step "these are the organizations doing LARP around here, this is what you likely will encounter at your first one, these are common etiquette rules, these are common pitfalls, this is how casting works, here's how you tell if it's good for beginners..." Most beginner classes and panels I see err on assuming basic knowledge because the teachers have been doing it so long that it really is basic knowledge to them. I'd like to see someone skip that and get down to explaining all the tiny little details that make me so nervous about actually going to or signing up for a LARP.

I'm sure someone's already suggested the "sexism/racism in game culture" panel, and you could break that down several ways since the different areas of Game Culture are sexist and racist in different ways, but I'd certainly attend whatever version of it you ran. For that matter, I'd like to see one that branched out from "Gamergate! Internet trolls!", assumed the audience already knows that Game Culture is indeed frequently racist and sexist, and got into the more subtle variations that people are more likely to encounter in their real lives.