This is a really nice piece, thanks very much. Perhaps some comments, more general in nature, are in order.
First, going down below 40 nm, no matter what radiation you use, the resist is going to limit you, either in throughput or resolution. Particularly these chemically amplified types.
Second, at the same dose, smaller features use less incident particles (photons, electrons, etc.) so are naturally more prone to random dose variations (sometimes called shot noise).
Third, the CD vs dose model needs to be discussed much more openly especially as more critical features are being added.