DU's Hockey Alumni Association began selling 50-50 tickets last season in Magness after procuring a raffle license. It was a rousing success.
Probably not a good idea for Booster Clubs to raise money on campus or to hold meetings on campus for the reasons you mentioned. Hold those activities at local restaurants, publish your own newsletters, website and blogs off-campus.
In this day and age it is a real good idea to keep your boosters and alumni far away from the student athletes.