A:AnswerYes muted very well outside sounds I listen to my speaker pretty close to me while playing the game & loudest and I barely hear it but can I make out the words and sounds? Yes
A:AnswerI have yet to try it on my mobile device, but I have to say that it works amazingly well on my PC. Highly recommend actually. Me and my brother both use this headset for serious gaming that sound quality is absolutely key for.
A:AnswerIf you keep the headset plugged into your controller it will work fine as long as you leave the controller on. I haven't had any apps or games that didn't have sound with the headset plugged into the controller.
A:AnswerYes and no. You can do both. Make sure to check your Xbox settings for sound output and set it to headphones only and not the "Headset & Speakers" option. Also make sure to have your TV volume off.