If you are organizing an event, and someone else creates a FetLife event listing to promote it, give the caretakers a yell at firstname.lastname@example.org. We'll work with you to get it transferred over to you once you can show us that you are the event organizer.
Event planning can have all sorts of hiccups - venues cancel, presenters get sick, vice squad raided last week, etc. So sometimes you just need to delete an event that you've created. How do you do that? Simple - if you are the event creator, just email the caretakers at email@example.com, and they'll delete it for you.