public libraries event management module customization

We're a 33-branch public library in Ottawa gradually getting up to speed on Drupal. (Extremely early sandbox stage, let's say.) We have a pressing, and as yet unmet, need for handling event registrations at all of those branches. Our requirements include, among other things, allowing signups for a recurring class with multiple dates (i.e. one registration for all sessions), adding a waiting list, being able to globally start all registrations on a specific date, and being able to cancel a session and send an email to all participants.