I've never tried livestreamer, but gtk-youtube-viewer streams. Well, really
it just opens vlc or mpv with the url and the player streams it.
gtk-youtube-viewer can search, download, stream, display comments, display
the description, and search by channel.
You can view all playlists by a particular channel, but I'm not sure if you
can search for playlists independently of channel. It appears to be possible
to post comments, but I haven't tried as I would presumably have to be
somehow logged into a Google account.
