You'll need to disable Direct CD while using Nero - you should not have to uninstall it though. I only start Direct CD when I need it (for data backups) - I find Nero is just as fast for other file copying.You may want to disable Direct CD from loading at startup and load it on demand.
I think that Audio CD's have a fee paid for each CD and regular CD-R's don't. John can correct me if I'm wrong. You can certainly use regular CD-R's for audio or vice versa.