A:AnswerAs long as there is audio output going through they won't shut off. Would be pretty insane to be watching a video and have them shut off because you weren't talking to yourself. They only shut off if both input and output aren't happening.
A:AnswerNo - Wireless headsets without Bluetooth technology require a USB-dongle to be plugged into the PC or Gaming console they are connected to. As tablets and phones do not have a USB-A port, a wireless headset with a dongle - and not Bluetooth enabled - will not function.