I’m just guessing so your scrobbling can be associated with you. I can’t think of any other reason right now.

I’m not certain but it could be used for album art, album description info and for last.fm scrobbling, according to the documentation.

Have you tried Arduino yet? The website has a lot of good tutorial information. https://www.arduino.cc/en/Guide/HomePage should get you started.

I would like to have a kill switch on the PinePhone. I don’t know that the placement under the case is ideal but with ever shrinking phone bezels there is a whole lotta unused real estate on the phone’s back side.