Sounds like you've thought things through pretty well. One thing, though: the little subbie on my shoulder is whispering that it's not really fair to assign her an outfit and then punish her when it doesn't conform to your rules. The miniDom on my other shoulder says there's nothing wrong with setting up a readymade reason to put somebody over your knee, considering you could do it for no reason at all if you wanted...

I guess my advice is if you're going to "punish" for something like that with a sexy spanking or something else you both find fun, then that's cool. Just be aware that the feeling of disappointing one's Master can produce anything from a mischevious glee to an actual emotional ouch, depending on the tone you set for the punishment.