Several times I have seen a sound card just stop working in Windows for no reason. Removing and reinstalling the sound card doesn't help (software and/or hardware). You get to the point where you believe the sound card must have stopped working, but then it turns out that if you reinstall Windows the sound card magically starts working again.

In Linux, the problem you are having is because there is not a fully working driver for that sound chipset in ALSA as of yet. So there's no real surprise that it's not working correctly. It would be possible to change your sound server from ALSA to a new version of OSS that has support for that card, but it would probably be easier just to get a different sound card if you really wanted to run Linux on that hardware.

This is thanks to Creative's 'when they feel like it' support for Linux. You never know what they'll support and what they won't bother with at least for a while. Eventually it will almost certainly work perfectly, but I like my hardware to work when new, so I tend to favor other brands of cards. Only for gaming are Creative cards really good anyway. For other uses you are better off with Asus or M-Audio, and they are pretty good for gaming too.

Apple's GUI is certainly not open source, only the system underneath. You can run OpenDarwin if you want (you have to compile it yourself though), but you will be using a conventional Unix compatible GUI like KDE, GNOME, XFCE, etc. I don't like GNOME, but it's no more bloated than the Windows Vista/7 GUI. Personally, I find that XFCE, Fluxbox, IceWM, and/or other window managers work fine depending on the circumstances I want to use them under.

DRM is always a problem because it's designed to stop you from copying the media which is a problem when you want to be able to put it on any one of a number of your personal devices. I generally only use media that I can obtain or create a non-DRM version of so that I can use it where I want to (not so I can upload it to a "warez" site).