If you open a file...
When you open a file with missing links, don't you get a notification?
Also in later versions, (not sure when it was introduced), frames containing missing or modified linked content do indeed display an alert icon at the top, when not in Preview screen mode.
Opening a file with notificaitons of a missed link is your Preferences
In CS6 I beleive a Link icon was added to the frame - which indicates if an item has a broken link - not sure if that works on images or not.
And you can view all the links and their status in the Window>Links Panel
OK, so I figured this out. I had to go to View->Extras->Show Frame Edges to see the warnings!
Thank you sooooooooooooooooooooooooo much!!!! You have completely revolutionized the way I work and the way comic books will be made!!!!
THANK YOU!!! Thank you!!! Thank you!!!