I'll give it a go!
"In addition, in what capacity is the Operator account of value or can it be deleted? We have discovered that if people choose the System Directory Handler, they can "find" their way to the Operator voicemail by pressing "0" and leave a message. However, this voicemail box has not been monitored, thus their are over 300 messages in it.'
You can't actually delete the Operator (It's a default User Account). Just go into the System Directoy Handler, click edit > caller input > if you're feeling bloody minded, choose "hang up" on the "If Caller Presses 0", otherwise either create a new call handler or point it to an existing one.
"Our system is comprised of 19 different buildings, with 1 to 2 Attendant Consoles per building. When our phone network was set up, people who have Attendant Consoles did not want callers to have the option to leave a message if someone is away from their Attendant Console momentarily. Is this best practice? What are most companies doing with their setups?"
I have to deal with both situations. Some locations refuse a voice mail, some want it. It's normally at the wish of the department head. Just make sure that call does not ring forever or otherwise make the caller upset.
Gareth