If channels were to be removed, it would be more clearer to everybody including new users, what the real use and power of nix is, and all documentation would go straight to pinning. Then only after understanding this, can people write higher level abstract tools to provide an auto-updating "channel" like interface to the underlying pinning concept.

No pinning isn't about which channels you get. Pinning pins to a content addressed commit hash of nixpkgs or any nixpkgs even your own fork. Channels is orthogonal and probably a mistake and should be removed.

Calling over e-mailing has a number of advantages, you're able to empathize with the person and they're able to hear how comfortable you are with the topic over the phone.

Make sure you have a good headset with a microphone as any background noise is distracting to others during the call. If there is excessive noise on your connection, you will be muted until you need to speak. Make sure you join the IRC channel as links and code examples are usually shared over the chat channel.