A:AnswerYes, it does have 4K pass through and I have connected my Xbox x to it and got all the check marks. You need to change the HDMI to enhanced by pressing BD/DVD and the power button at the same time. Do this on the receiver.
A:AnswerYou can only use Atmos in a 3.1.2 configuration and for me personally I could never get Netflix, Amazon Prime nor any of my Blu-Ray movies to output Atmos at all. If you want REAL Dolby Atmos I'd avoid buying the system and at least get a 5.1.2 or a 7.1 that support true 5.1.2 Dolby Atmos. Buying Dolby Atmos speakers isn't likely to improve your sound if the Atmos you're getting is already limited to 3.1.2.
A:AnswerNOOOOOO, this draws it's power from the receiver and believe me it's an extremely WEAK subwoofer. Trust me, buy a separate powered subwoofer, it'll be a giant improvement.