If you mean the newer plug-in (not hands free) official headset then if the switch shows green you are 'live' and can be heard, or if the switch shows red/orange then you are on mute.
Yes you click the power button once.
A good gaming headset for Xbox 360 is a Turtle Beachheadset.
No, xbox 360 headset can only work with the 360.
no
yes it does. i got the xbox 360 elite and it came with a microsoft wired headset
yes
no it has to be Microsoft.
yes it does
Yes, it doesnt matter of the controllers or headset, there just different colors.
You cannot hook up a guest headset.
NO you can't
No you can not