q?=admin page accessible for anonymous How do I prevent this? I'm not sure what is causing this. This site is running over 60 modules now and yesterday I noticed something changed my admin_menu toolbar layout, but don't know if this has to do anything with this.
Check the user permissions. The anonymous role might have one too many permissions granting access, such as "Use the administration pages and help".

You aren't running any sort of caching setups that might be caching a logged in experience and displaying it for anonymous users are you?