A:AnswerYou don't need to change your light switch but to turn it on/off, yes, you need to keep the power on in order for that to occur using the hue app or Alexa.
A:AnswerOnce you setup the hub with your router, you can unplug it and plug the hub closer to your master bedroom. This will allow you to use it as a “WiFi” system.
A:AnswerYes. The app controls the dimming setting and can be set to 3 different schedules per bulb. Works best with smart hub, though. Bestbuy has had this and the Amazon dot bundled for $50 from time to time