@Tenth Letter:
Please note that this is an immediate solution, to test if your application preferences are damaged, and cause the crash.
If this does resolve the current problem, please close QuarkXPress.
Navigate to the following location:
Mac HDD> Applications > QuarkXPress 8
Delete the folder named "Preferences"
Now navigate to the following location:
Mac HDD> Users> Your Username> Library> Preferences>
Delete the QuarkXPress 8 folder
Empty the Trash
Now relaunch QuarkXPress
If the same does not work, please pm me your contact details, so we may contact you to resolve your problem.