Armoury Chest

[Mjollnir]

But then, how do we select the class/job we want to use? We just repeatedly have to select each piece of gear one bit at a time every single time? There must be something else that they haven't revealed yet, because the only way it would work without Gear Sets is... I don't even know.

Oh no! This is the Armoury Chest, merely for storing equippable gear. The Armoury Board is where the equivalent of gear sets will be administered from, using pieces stored in the Armoury Chest. Here's a link to a still from the Live Letter the Armoury Board was showcased in.