Yes, I do know that, for sure. I never have, but have witnessed some pretty pitiful situations at Christmas parties. What are these people thinking when they upchuck into their bosses lap? LOL
Well, they aren't thinking about promotions, that's for sure. :) I'm sure many might disagree with that.
You'll be wonderful. You can talk to anyone.
About those heels, one inch pumps are very acceptable and some are quite comfortable and if you find some that are cut low enough to show the V between your big toe and second toe, they will be considered quite sexy and classy. Plus, you will be comfortable.
Remember, do not twitch, shuffle, pull at your clothes or adjust yourself in anyway, or fidget. Get all that straightened out at home and get comfortable sitting, standing, walking, maybe dancing in whatever it is you plan to wear. Do a dress rehersal the days before your event and remember to break your shoes in. Then, you'll be self confident, won't be or look awkward, etc.
I know you know all this but we all need reminders and I love this stuff. Thanks for asking and you report back to Mother after the prom, you hear? LOL.