I've got that card, but I don't have the VIA audio control... I actually don't have any control features. Just standard windows controls. I'm using the optical out from it, so I don't ever need to mess with it.
I'm not sure on Stereo EXpander myself but from
here it sounds like it plays 2 channel on more than just the fronts.
I imagine center/lfe swap would switch which portion of the stereo jack is providing the signal... like swapping left and right for stereo but on the jack for cener/lfe (lfe = low frequency effect = sub channel)
Maybe Immerizo 3d is like EAX for creative cards? Really not sure on that one.
This might be a sign I should update my drivers.... of course I don't think it's going to do anything to the digital output... maybe I should leave it alone since it's working heh.