I think you should run CTCM.exe and see how you go - it should hopefully autoconfigure around the onboard sound. If you don't get it working I remember the awe32 not sounding all that good with duke3d anyway (personally I thought the guitar sounded a bit 'funny'), so not a huge loss if that is what you are primarily using it for.
RE: multiconfigs
I've got 4 configs in a menu in my startup - two of them go to http://surf.to/AccessDosMenu (a nice graphical menu app). One for demos and another for games (I leave off cdrom and emm386 in the demos config).
One is a minimal config with nothing loaded, and the remaining one loads cdrom, 4dos and sets up a few aliases. It's good to have a bit of flexibility in your startup I feel - as a lot of games/demos don't like having certain things loaded.
RE: Win98
Actually I've recently found one good reason why win98 is handy.. I was trying to get the 3dfx versions of blood & shadow warrior going (these only work on the original 3dfx) and it requires windows to be running (they want to load a glide dll).
Dual booting is a pain however - haven't been able to bring myself to do it (I hear 3dfx blood isn't all that great anyway) - but I suppose I might one day.