if you go early on the friday, get settled in your hotel room and then get in line, or take shifts with someone else if you want to be early. the door will not open before the line starts forming, so its literally first come first served, yet serving will begin when the doors open. if that makes sense.
the line USUALLY moves fast, but i've also seen it go on for quite a while. your best bet is the shifts idea, if you can get someone to go with you.
I agree with the allergies. Its best to leave peanut products and oranges at home or at the very least keep them in the hotel room. I'll update the con etti list mentioning both that and the music.
The music is for raves or maybe for outdoor stuff. (i know i've seen people do the caramelldansen outside in large groups)