hmm...ok, so what are your specific questions?
let me see:
1. sound quality should be *better* (due to swapping of front/rear channels) what speakers are you using? 5.1? or standard stereo? -i've found that with my speakers (5.1) if I uncheck the "swap front/rear" in the mixer, then i get almost no bass. this is due to, er...well, i'm not *entirely* sure but It seems that the front/rear bass cancels each other out. maybe this is what you are experiencing.
2. direct sound output in winamp *should* work perfectly. it does for me anyway. are you using the latest drivers?
3. yes, kx drivers lock the sample rate to 48khz (and yes, it's for a good reason, and not just to annoy you!) the problems you will encouter will be if the program you are using does not support 48khz. most do, but some (rebirth for example) doesn't. this means that the sound will be out of tune.
4. to take advantage of the reduced latency, you will need programs which support ASIO. if the program you are using doesn't, then you should get just the same latency that you did with the standard drivers.
5. Rebirth doesn't support ASIO, but i've never found this to be a problem anyway. (i use it with Cubase)
ok, maybe not much help there, but at least it clears up what should and shouldn't be happening...