I didn't go to USF, but again, about the class thing - I was elected VP of Alum and Parlimentarian, and then I had a required class that conflicted with chapter meetings. I had to drop the Parlimentarian postion (yeah - imagine that the Parlimentarian actually had to BE at the metings

), but I was still the VP of Alum...and I know we had regular (non-office holding) members who had conflicts and it wasn't a problem. They just had to read the chapter minutes and were expected to get info for all events coming up from either the Secretary or another sister.
Like previously said - you're in school to get an education, not to be in a sorority.