Yes, you can delete event attendees but your would have to do this one-by-one, from within a specific event. To do this open an event click on Attendees list and delete all attendees, one record at the time. Unfortunately it is not possible to delete event attendees in bulk.
Events cannot be archived. You can simply leave them as past event or you can delete them.
Denys Zlobin
Helpful Apricot
http://www.wildapricot.com