Is there a way to send an annual Reminder to 'Open: Emails sent openly to anyone' and use a customer email address?

Since Subscriptions and Reminders can only go to QuickBase Users, you would need to have a Subscription report go to an inside staff member and have them click a button on each record to fire the Notification.  It's probably also possible to reduce this to one click to fire off a small script which would walk down that report to trigger individual emails.