A few quest items added with the last update caught my eye that might be related to COR and possibly unlocking it.
Forgotten Hexagun - An old hexagun found in Talacca Cove. It is broken and unusable.
Bag of Gold Pieces - This bag is so heavy that it requires two hands to carry from one place to another. There must be a fortune inside...
The first item is self explanatory. COR use hexaguns, so the quest might involve finding this hexagun in Talacca Cove (wherever that is) and bringing it back to the quest NPC. As for the bag of gold, maybe the NPC requires payment or "booty" to refine the gun into a functional weapon.
Keep in mind this is purely speculation, but this would put to rest the questions about why we don't get a gun until level 15. If the Forgotten Hexagun is turned into a level 1 gun (given to you when you unlock the job), then we'd actually be able to use our abilities.
Just a thought