Witch-king is was too awesome of a fate for Kemen, but I definitely agree that he becomes a wraith. Theo as King of the Dead would be great.

The dark wizard being Saruman doesn't really make sense, which is why I'm afraid they'll do it. I wish that the stranger and the dark wizard had both been the blue wizards as that fits more with the chronology and also opens up lots more avenues for original stories.

Celebrimbor and Annatar were the highlights of season 2. I loved Celebrimbor's tragic ending but also that it ends with a prophetic pronouncement of Sauron's final undoing.