Some users Notification settings being reset to all OFF...?
Using Jamroom
You really don't have to worry about "inadvertant" clicks - if someone does accidentally click on it, they are told they are "unsubscribed", but there is a big "undo" right there so they can back out of it.
If you need to change the footer (add extra space, whatever), modify the "email_preferences_footer.tpl" template in the User Accounts -> Templates section.
Let me know if that helps.