I agree with all of those castings, crozack, with the singular exception of Laura Allen. I had the extreme displeasure of being cursed watching her character on 'All My Children', and the girl just doesn't have the versatility to play a character as singularly, inhumanly detached as Narya. She just doesn't have the bearing.

Being the big Farscape fan that you are, have you considered Virginia Hey portraying Snowbird? She's a very regal, statuesque woman, and she retains that bearing even in a casual setting (I had the pleasure of meeting her about a year ago.). She even has the face, and I think that's important, to capture her elegance in totality.

But as for the rest, I think you're pretty much dead-on.