The racist guy was really a nothing. They didn't even properly sell any of his motivations. Yes, he potentially could be something, but as it stands, nothing he did amounted to anything at all. The story was really quite vapid and only served to talk about Rosa Parks, not develop any sort of story.
The Morax weren't effectively dealt with either, just imprisoned to become someone else's eventual burden.
None of the other antagonists truly qualify as villains.
Yes, but this Doctor is not an interesting thing for a holiday special.
If anything, I would say New Year's is TOO interesting of a holiday for a special. Christmas is the boring holiday where people sit home and be bored at the TV. New Year's is where they're too busy having fun to watch TV.