I really don't like the idea of the Vampire Lord
Unless they polish it up to a much greater degree, and implement it in a believable way in the game, which means above all, make Vampyr Lord hostiles (highest caste of Vampire maybe?)
I have a problem with the lycanthropy tree as well, not because it's a bad idea, but because Werewolves were mishandled in Skyrim from a lore perspective.
Dragon Mount: Absolutely not. Aside from looking goofy, it undermines the size of Skyrim to a degree that makes me question just how much the author of this article knows about game design when he says "Dragon Mounts could make Skyrim
Bigger.