Brilliant! I was going to post something very similar, but I couldn't have described it better. Love the little touch of credits rolling during the tickling. Less is more when it comes to little TV moments - makes it more special, rare, and desirable. That way, we get our little tickle clip, and everybody else gets to enjoy the game show with the fetishy stuff happening only at the very end as a little bonus. Though the idea of a full tickling game show is fun, yours is probably the most realistic scenario to happen in real life - just short enough at the end to remain family-friendly.
Love the box idea, too! It's my favorite contraption for foot tickling. If I were to add to your idea, I think it would make sense for the theme of the game to tie into the tickling punishment at the end or it would just seem random. Perhaps multiple rounds of try-not-to-laugh challenges like you see on YouTube, or like Impractical Jokers (see The Name Game, for example, where the most laughs loses.) Also, so there's guaranteed laughter at the end, they would find contestants at pedicure places so only ticklish feet make it onto the show.
And realistically, the punishment at the end would have to be optional. But much like Jeopardy, for example, where runners-up get a smaller prize, the prize here for last place (the loser) would still be substantial enough that they couldn't say no! (The last place loser can go home with nothing or accept the punishment and collect their prize.) I would relish the moment at the end where a lady is torn between getting her ticklish feet to safety out of the building but leaving empty-handed or the prospect of having some considerable spending money in exchange for some wild, humiliating, public laughs!
This show would be unique in that, while people watch other game shows to see who the winner is, this show is all about the loser!