Is there a way to return a ticket once you buy it? I can't get another ticket that crosses a given time slot, so if I find something else I want to do can I return the original event ticket to attend a different event?

You can, up until the mail-out date, for system credit. If you call in, I think you can also get it refunded to the card for some small fee (like 5%).

~Komori

System credit would be fine... when's the mail out date? I'm just worried about locking myself into a schedule and then having something new come up and want to swap out some events. Thanks!

June 16 is the last day to return tickets before the packages are put together.  After that, you'll have to return any tickets on-site, which will block you from signing up for another event for those 6 weeks.