How do I let non-admin user approve comments? I'm looking for a way to allow a non-admin user to approve comments. I thought a Flag/Rules combination might be a solution but I can't figure it out.  

I added a content-moderator role, then I created a view listing comments awaiting moderation. After that, I set up a flag to approve comments and added the flag link within the view, bu there is no Rules action that approves comments once the flag is clicked.  

Do you have any idea?
You need to give the "Administer comments and comment settings" permission to the role and then it will be able to approve the comment.