Your first post on this community indicates that you have already returned the BEAM.
You purchased the wrong product. My suggestion is that you purchase a product that includes a simple handheld remote control and exclusively uses this remote to control the device. However, this sort of device will not provide easy access to online music services, but your TV might be able to provide this access.
A basic A/V receiver will satisfy your control and privacy requirements --- but you’ll have separate speakers to wire.
Your post is confusing on many levels.
“So all audio to a Sonos speaker must go through the Sonos app, no exceptions. No Sonos app, the speaker makes no noise.”
No. If your music service app has the feauture to make you play music directly to the speakers, like Airplay or Spotify Connect, you will never need the Sonos app aftre you've set up the system.
“Use the Sonos App to launch Pandora as a test to get some sound.
Close Pandora and Sonos apps music keeps playing,
Close all apps, speaker keeps playing. Turn off phone...speaker keeps playing.”
“Finally pull the power plug to stop the music and turn off the speaker since there is no power button?”
You do not seem to understand how Sonos works. When using the Sonos app the speaker will not get the music from your phone, but will fetch the straem from the internet by itself. Stopping or even uninstalling the Sonos app will not tell the system to end the sream, so it keeps playing. There is a touch sensor on top of the Beam that will make it stop though. No need to pull the plug.
“Turn on phone and start Pandora, Pandora says that another device is actively logged on my Pandora account. Music plays independently and simultaneously on both phone and Sonos speaker.
Reinstall and start Sonos App and it will not connect to Beam 2 speaker, asks for GPS, WiFi and Bluetooth to be turned on, and still will not connect. Music keeps playing on speaker with no ability to control it from any device.”
Not sure what you've done here.
“What is with the Sonos Beam 2? Never in my life have I had an application hijack an App and then I have no control over it? The Sonos App and Beam 2 appears to offer no control even though it takes control of your applications. Very concerning hardware and software.”
You might want to read up on the expensive speaker you've bought and it's functions.
