Shooting a Sorority Formal..need advice

Hey guys, will be helping out a friend with her event in a few days and was wondering if you guys had any tips or advice on what to bring/do.

I'm primarily a landscape/cityscape shooter so I'm not too good with portraits.
I have a t2i, 17-50 vc, 30 1.4, 11-16 2.8, 24-105 4, and a 430 ex ii, tripod and monopod
No strobes or anything

Is it necessary to bring backgrounds or whatever? I figured I could get away with using the wall as a backdrop and the 30 1.4 on single/couple shots while using 17-50 or 11-16 if really necessary on the entire group/sorority while using the 430 the entire time.

Also, the venue itself is decent sized so I think I can bounce light off the top but I fear it will create some shadows on their face so I was also debating whether or not to use the stofen omnibounce straight on their face to possibly get rid of any possible shadows.

Also, any ideas on what to do for group shots? Like aside from normal serious/funny pose, jump pose, or ionno, any ideas would be awesome.

-Jo

rent some studio lights, pocket wizards and buy a muslin background. set up a photo booth area. shoot the groups there.

for the walking around the event pics, use either the 17-50 or 24-105 coupled with your 430ex. for me, omnibounce just wastes light. use you 430ex bounced to the wall or ceiling with a white index card for front fill. how high are the ceilings?

I'm not really getting paid for this so I'd rather not shell out money for this as this was also somewhat of a last minute request.

Venue: http://www.montecristo​banquethall.com/aboutu​s.html

Also, ty for the input.