I realize I could probably test this out myself, but I don't want to mess anything up. I noticed that in the inventory, the right-most option contains all my DLC, whether they're the free item packs (which seems obvious, use the pack to redeem the contents) or things like Mystic Artes, Skits and Costumes.
Do I actually need to hit X and use these items to redeem them, or do they trigger appropriately when Mystic Artes should normally be unlocked, when I have met the conditions for the skits, found a clothing store or something, etc?