Possible Clues:

• Crones (anag) — (person with powers to) make cuts in letters, plays etc
• He cuts corners wrongly - only one right
• One vetting films, etc
• A banner of films and books
• Use a seven-second delay, e.g.
• Magistrate's expression of surprise being put inside
• Show snipper
• Ban (part of book, etc)
• Blue pencil wielder
• Check contents of letter, play etc with a view to deleting passages