i have found that Pause and Exit are the only two admin buttons i want on my panel. everything else is used so little, it is better handled with button combos, or a keybaord. One thing to watch out for, it people accidentally pressing the exit button (happens with kids alot for some reason) it sucks when you've spent 20 minutes playing a game and someone exits your game for you.
i have handled this several different ways. on one of my cabinets, i had a single admin button, and used autohotkey to make it serve a dual purpose. if pressed normally, it pauses, but if pressed and held for 3 seconds, it exits...that way you have to want to exit. on another cabinet, i have a dedicated pause and dedicated exit button, but the exit button is still on a 3 second hold. on my friend's cabinet, he has two pause buttons (mapped to two different inputs on the ipac)...if you press either one, it pauses, if you press them both at the same time, it exits. this works well also.