According to 1d4chan, the SpaceWolves, along with the Black Templars, World Eaters and Khornate Worshipers are some of the most genre savvy people in the entire Imperium. Not that there isn't plenty of it to go around, with the Imperium's official policy of Shoot Everything That Moves being a product of them realizing they live in a universe with Everything Trying to Kill You, and the Imperial Guard being completely aware of their Redshirt Army status. However, among them all, it's the three Space Marine chapters (and Religion of Evil) that really take it to an extreme, actually realizing that they all live in a fantasy universe with spaceships.
Not lemures, lemurs. This is a Shout-Out to an art mistake in which an artist confused a lemure (a spirit of restless dead in Roman mythology) for a lemur (a small tree-dwelling primate). Norin is making the same mistake the artist made.
Changeling: The Lost pulls this like no one's business. It's common knowledge in game, for instance, that the Wyrd likes to play Literal Genie, and the Autumn Court essentially specializes in this Trope. And then there are the Talecrafting rules in the sourcebook Swords at Dawn: characters can purposely force Tropes to occur at will because they realize their own lives work by the rules of stories. The book actually suggests TV Tropes as a good place to find examples of patterns to use!
Metagaming is actually an option for player characters in Grimm. The Gaming trait covers knowledge of such things as fairy tales, fantasy novels and films, fantasy card and board games, narrative video games, and the game Traps and Trolls. Since it covers not only knowledge of fairy tales, but things that are either directly or indirectly inspired by them, you can use this trait to cast or identify spells, recognize fairy tale settings or characters, and determine the weakness of fairy tale characters.