Why does nobody get the Banshee?
For starters, I haven't read the original novel. But in the case of the Banshee, I don't think its necessary.
Everybody argues why the Banshee looks so awkward and artificial. It's totally on purpose. Just look at all the flashback scenes with Lipwig's bad deeds - they're all nods to the history of cinema and filming. The Banshee represents the dark fantasy characters of that era - not exclusively, but including - Lugosi's Dracula. The overblown acting and the similar outfit immediately snapped it in for me, and I thought it was both hilarious and genius (another such nod to old cinema: old-school fast-motion in some humorous scenes).
If all the negative characters were portrayed with strong dark parody, I don't see why the Banshee should have looked horrific and frightening.