You should really make a new kernel with no OSS drivers at all, and exactly pick your card from the list under Sound -> ALSA -> ISA drivers.
Every card will have options - the CS card must be like a WSS clone, will have a control register range at 0x530 and 0x538 - will probably use DMA 1,0 and IRQ 5 - SB emu at 0x220, FM at 0x388, synth at 0x330.
You should put these in /etc/modules.conf as "options" statements to the (aliased) low-level drivers.
This is the driver part - and is fairly simple - do it from RL3 (no X), yast2 at the command line, then configure the hardware once the new kernel is in.
While you are at it, it's a good idea to just have done with it and make the proper kernel now, with the correct processor type and features, power management tailoring (really important for Thinkpads), IDE chipset etc. There is just no way around this if you don't want something that is just "Windows for Geeks".
After all that is done, you can then deal with ARTS, which is what KDE needs. You really do need a high-level interface to sanely use ALSA. The whole point is to abstract the sound interface - so it's worth it to endure crashes - I've noticed a horrible leak in my setup for the Toshiba, which is very carefully made and so I'm certain this is a real issue - unfortunately I have no desire to track it down, it's an old machine. So I don't know a lot about ALSA in action. I tend to have a silent UNIX experience by choice almost. I never quit until sound works! But the main thing first, to make it sane, is to have an exactly tailored kernel.