Using Show 5 to control Sonos One and grouping question

PART 1: I have a Show 5 and Sonos One in my kitchen. I want the Show to be my Alexa device, but would like the One to be my speaker for music in the Kitchen. When playing music, I don't want to have to specify “kitchen” in my commands. I created a group called Kitchen, and added the Show and Sonos One to that group. The Sonos One is set as the speaker for this group the playback option is set to “Always.” 

Question… Did I set this up right? Should I turn the mic off on the Sonos One? If yes, is there a way to disable the mic so someone (i.e. one of my kids) doesn't press the button and turn on the One’s mic by mistake?

PART 2: I have a Sonos Beam in the living room, which is next to the kitchen. It is connected to my TV via HDMI. Sometimes I want to be able to play the same music through both the Sonos One and the Beam. I created a group called Living Room, and then grouped Kitchen and Living Room into a group called Downstairs. 

Question… Sometimes, when I'm in the kitchen and talking to Alexa, the Beam in the Living Room responds. I'm like 2’ feet from the Show, and 20’ from the Beam. Why the heck is the Beam responding?