While setting up your summit, you would like to know more information about deleting and customising tickets.
When you delete a ticket type under Revenue > Tickets, the attendees who held that ticket will still have access to the content as per the permissions of the ticket before deletion. This means that after you delete a ticket type, you will not be able to edit the access of these attendees. If you don't want them to have access anymore, or want them to go through the registration process again to get a new ticket, you could delete their attendee record.
If you're looking to have a ticket for your event that is only available for purchase for a certain period of time, you could set a date range under Revenue > Tickets > Edit Record > Prices. The ticket will be available to select at checkout up until midnight at the end of the 'Active to' date.
To set up a ticket so that the associated content is only available for the attendee who holds it to view for a certain period of time, set the date or access period under 'Set an Optional Expiry Date'.