+1
Should be one partition for OS & applications, and one partition for data/documents, at a minimum. All modern Windows OS's make it very easy to redirect the contents of "My Documents" to a drive other than C:.
Been there and done that, I always ended up with spare space in the program partition but out of space in the data partition. The problem gets worse the more partitions you add.
Multiple smaller partitions made sense on the amiga where a reboot would cause the filesystem to validate, but I'm not sure what problem you're trying to fix with multiple partitions per drive on windows.
With multiple drives I'd still probably try to raid0 or span them.
