Complete Monster: Several notable ones; Dr Leonard K Wisbeech (Others), Nell Quick (Once...), Sir Max Hubble ( '48), Alexandria Moker (Nobody True), and Boris Pryslck (The Dark).
Designated Hero: Joe Creed of Creed. Lampshaded by the narrator occasionally referring to him as "our hero" in a tongue-in-cheek manner.
High Octane Nightmare Fuel: So, so many to list. Domain in particular, is pretty much nothing but High Octane Nightmare Rocket Fuel without any respite for either the characters or the reader.
Nausea Fuel/ Squick: Herbert is very, very good at invoking this reaction in the reader.
The Woobie: Several. Fluke is one, and so are most of the horribly deformed "patients" of Dr Leonard K Wisbeech that Nick Dismas encounters in Others.
Iron Woobie: Nick Dismas, the protagonist of Others. In his previous incarnation he was a borderline Complete Monster, and he was reincarnated as a deformed baby in order to redeem himself and gain entry to Heaven, but you'd have to have a heart of stone to hear his life story and not feel sorry for him.