NOTE: This was orginally included with my review of the book I did over on my blog. Look up Spongey444 Wordpress/A Taste of Spongey and then Revenge R Us and hopefully you will find it. This was a messy non balanced 2000 entry so here;s some suggestions to improve it.
First off, Micah is toned down, but that goes without saying. Same goes for the parents, make them more oblivious and less terrible. Anyway, in this version Revenge R Us is more of a prank shop, but the items used for pranking are magical in some way.
Wade gets an item and uses it on Micah, which works. But instead of leaving it at that, she presses on and gets another item. Micah finds out about this after the first prank and decides to get an item of his own. This basically starts a prank war, but with magical items, leading to tons of chances for humor and scares. That's the bulk of my idea here, I just love the idea of a magical prank war.
Plus, I'd make things more even so that no one really has the upper hand and both parties are guilty in some way. As for other details, perhaps have a secret room in the store that has items no one is allowed to touch and of course eventually they go into it and find potions that lead to even more trouble and of course some major scares. Maybe they both becomes beasts or something.
I'd have it so in the end, we see what happens when you take revenge too far and perhaps they could talk things out and start to actually understand each other. They both learn they should talk things out and actually try to reach an understand. Micah learns to not be a jerk and Wade learns that mindless revenge just leads to more revenge.
I even have a twist ending if you really need one: During all this, Wade blows off Carl many times so she can focus on her silly revenge war. In the end, Wade and Micah go back to the store to apologize for everything and while they're say, cleaning the backroom to make up to Iris, they hear Carl come on and tell Iris about how he's been wronged by Wade, and he wants a little revenge.
Could be a bit cruel after she learned her lesson but eh, they could come out and apologize after hearing it, leave it open for anything to happen. Either way, I like my idea because it's balanced and could also be fun. See ya next time.