I have almost exactly the same setup, including the use of Debian as the server OS. I use Ampache for remote access (if I'm at a coffee shop and want to stream music from home to my local laptop), but log in via ssh and use moc when I'm at home and want to listen to some music on the server. Basically I use Ampache when streaming music from the server to a local machine, and use ssh and moc when I want to play music from the speakers that are hooked up to the server. You could try a similar approach, depending on how comfortable you are with the command line and console.
Not sure about the bittorrent question, but TorrentFlux looks promising for what you are interested in.