A:AnswerYes this headset does have an adapter that fits specifically only for the Xbox controller, so no you do not have to buy the Xbox one stereo adapter
A:AnswerIf you have an Xbox One, you can go to your left panel, scroll down to settings and the headphone/chat settings will display there automatically.
A:AnswerYes. It is a headphone with a mic. It can work on any system that uses a combined jack for sound and mic. PC, Xbox, PS4. Xbox One X is the same as Xbox One and Xbox One S, except its faster.
A:AnswerHe has to make sure the button on the cord is turned upwards/on. If that still doesn't work it could be his controller itself which has happened to me before the inner piece sucks on most of them or he just had a faulty headset and should swap it immediately. if the second headset still gives him issue I'd check to make sure the controller actually works.