It should be activated within the next 48 hours or so I would of thought.
Your best bet is to stay patient, if it doesn't come within 48 hours from purchase, I would open a ticket.
Is the domain already registered? If so, please see http://x10hosting.com/wiki/How_to_Use_Your_Own_Domain
AS for the backup, you can restore it via the 'Backup Wizard' in cPanel.