Very, very nice mission map. I'd like to hear, that you will make more maps from this fabular line. But, as always, you will do what you want.
And here's one advice - make Vaztumir selectable like hero. It's too easy to lost him in battle.
But - coming back to Angmar, i would really enjoy seeing mini-campaing showing us, how Witch-King united his kingdom for the first time. How he recruited Mornamarth, Hwaldar, Karsh, Rogash, Gulzar and rest of the heroes. That would be really epic. ^^