Possible Clues:

• "___!" / "Are you sure you're on my side?"
• This might lead to a Gael
• After time away drink gallons for good luck!
• Set a stone up, bearing a good luck wish
• Wish for actor to end on crutches?
• Require surgery on limb? Good luck in the theatre!
• Theatrical statement that'll make work for the setter?
• Thespian's good luck! (slang)
• Be lucky, then get gale?
• What you must do, to answer each pair of starred clues