Can't decipher question 1 as to what you want to do. Do you just want to change the Operator's extension number to something that is already in use, or you want to make someone else the Operator? Could you expand on what you want to do.

Question 2 - what is the senario? A call transferred to an extension and unanswered? An incoming call answered by the Auto Attendant, but the caller hung up instead of selecting a destination?