Some nice ideas in there. Particularly the manual validation! Given I am importing from AD I really don't see why the user should have to vaildate the email address since we know it's valid. All the validation does is give a user a way to avoid the alerts!
One think I would love to see, but which I fear may be pushing my luck a little too far, would be to have some sort of resource available in the core Orion product. At the moment my summary page has a resource showing all the active alerts. As I would like to move all the alert handling to Alert Central it would be nice if I could replace that resource with one generated by AC. Also means one less web page that users would need to have open if they can see their alerts from a page they should be keeping an eye on anyway!
I'm also hoping that "escalation to a management group" (or similar) is included in the "Providing more notification options" 