Oh wow, yet another thing to get excited about. In '04 I stayed with like fifteen other people until the thing was done (The dance floor was absolutely empty). I was sixteen then, but was wearing my Caine mask so nobody really check me (That and the Yojimbo's were trying to be nice and let us youngins have our fun). Last year I managed to stay most of the way through it by finding random people to call a guardian until I was finally told to just get out and go back to my room (lols). This year I'm 18 (!!) so I get to stay out however late I want. I wouldn't suggest the little folk bend (break) the rules as much as I did, don't want to give the volunteers a headache.
This year sounds like the dance will be the best yet. Don't worry too much about requesting, the DJs usually hit up all of the songs you want. Two songs I've had to request both times that went over well (and are essential dance songs in my book) are "Ice Ice Baby" by Ice Cube (Eat your heart out) and "Bohemian Rapsody" by Queen. Hopefully we'll get those played again this year.
I wore combat boots both years and that was alright. I wouldn't suggest any sort of mask or thick headware (I wore a paintball mask and my head was covered by cloth) as it will get decidedly hot. Also, capes and long gowns should be left back in the room. Ripped my cloak more than once at those dances.
About dancing: don't worry if you can't dance, I can't, it doesn't really matter. Do what's fun, no one will judge you. If you want to dance with someone, just walk up and ask if you can dance with them. Besides having a boy/girlfriend, I doubt they will turn you down. (I asked five or six pretty girls to dance last year and I was only seventeen. None turned me down.) If there's no conga line going, try to start one by asking those around you. That's how those things got going last year. Remember, it's all for fun, so don't hold back or be timid. I've seen many shy people come out of their shell on the dance floor and have a great time.
Umm... I think that should address most of the questions that were asked. Sorry for the long post, but I just want you all to have fun.
One last note: Don't leave stuff around in the actual dance room. I have a Seras Victoria figurine stolen last year after I hid it behind a trash can. Don't make my mistake.