This seems like a great fit and so does partnering with steemmonsters, though I'd bet they are mostly focused on getting the game playable by September.

I think @themarkymark would want to see Steemit represented at comic-cons, if he'll forgive a total stranger tagging him for his input.

Since you're looking for ideas, I suggest making a new post soon that is more like a pitch. Start by presenting how awesome it will be when people are signing up for Steem accounts right from your booth and the introduce yourself post is buzzing with users who met each other at comic-con. Don't start with "I am pretty sure this approach will fail". I almost didn't click past that preview in my feed, and all I had to lose was a few minutes reading time over coffee.

Let people who have something to lose see how much they can gain, to get their interest.