yes, the 2.5 kernel can "hotswap" kernels without a reboot. This will definately be included in the 2.6 release. Although I fail to see the real advantage of it (especially for a desktop), wouldn't you have to kill all processes, dump all modules, then swap the kernel? Is the 1 minute post really that aggrevating? maybe i should do some reading or get the latest 2.5...
as for the windows partition, if the "umask=000" doesn't work, drop a ",rw" right after it (no spaces). It might be getting mounted read-only. check your boot messages.
-t.