For auto-ripping I use a script called 'abcde', works well, I just insert a CD and a directory for it appears in my mediaserver where it also gets uploaded to Google Music. Uses standard tools, very configurable and I've not had a problem with it getting the metadata: http://lly.org/~rcw/abcde/page/
RE headphone output, have a poke about in the mixer. I usually find that with everything turned up max the output is too loud for 'line level' and so gets clipped. Later versions of alsamixer show a 'db gain' value which for the PCM channel seems to be zero at around 74% on an AC97.
RE playing, I've given up due to having to 'declutter' the wires all over the house, now I play from Google Music on my phone to the Hifi using a Bluetooth A2DP receiver. Far from ideal quality wise but it's convenient, lets other people join when needed.
When the house was wired up I had Amarok running in VNC on the server with a smart (random) playlist and Amarok Remote on the phone. I also had scripts to pick up the output of other PCs' music players using Icecast.
Neil