1: How do you get rid of the iCal dates? See link.
Do you want to just remove the iCal links or the full date list?
2: We have duplicate tickets we cannot delete. There are no registrations for the tickets we cannot delete. See link.
You mean duplicate datetimes? If you click the cog icon does it show a ticket set on the datetime (you will not be able to remove them) just check if a ticket is assigned to it, based on the screenshot there will be and its expected that you can not remove them if tickets have been sold for that datetime.