A:AnswerYou have several things to consider here...
1) The V405 series is Dolby compatible.
2) Dolby Atmos requires a 5.1.2 or higher speaker system for Atmos imaging. Regardless of the input, with no soundbar, you will only get stereo out.
3) Dolby Digital (the broader set that encompasses Atmos) is incompatible with DTS.
However, BOTH Dolby and DTS are supported by the V405.
A:AnswerI've tried with my Xbox Series and I couldn't do. Up this point, at least. I don't think so. In my Xbox settlngs appear: "This TV doesn't support 120".
A:AnswerYes, the amazon firestick plugs into one of the three available HDMI ports on the back of the tv. I plugged my firestick in and it is a nice addition to the tv.
A:AnswerInput voltage is only specified 120V AC 50/60Hz.
Having had personal experience from living abroad, I would say 220V would let the magic smoke out - and it would no longer work.