I've done a little research since this post.
RE: ICE I believe that it works by scanning in IR. Color film is poque to this whereas B&W is not. It interprets info in the B&W negative and dust and scatches and adjusts with disasterous results.
RE: RGB vs greyscale. The online help did not mention whether to scale B&W in RGB or greyscale. However, I went back and read the manual. Its says to scale B&W in greyscale.
I have been scanning as follows: 14 bit, greyscale, and Neg mono. I'm quite pleased with the results, although even the slow (100) film seems grainy.