iTunes already has a solution for this: shared libraries. It's much, much easier to configure than NFS, and it's fully supported. Why do you demand the ability to reinvent the wheel?
(Also, iTunes will play ogg files if you install the Xiph codecs for QuickTime. This has been the case since at least 2006, and you've stated that you last used iTunes in 2007, so I suspect you're not even trying to be fair in your criticism of iTunes, which is a shame given that there are plenty of real problems with it.)