Glamour Issue.

[Imoen]

I suspect this is purely for animation reasons. They linked it to 1 handed animations because it made sense, it would be silly to make specific 2handed versions of the animation, and if they were to invest the time in a 2handed animation, it would be best if it served multiple purposes for other weapons in the future, that they would actually use. It's not impossible though, just unlikely. (bang for buck, if the ff13 weapon is going to require a whole new animation for that style of weapon, why make it, if it is literally the only one in the game that will use it?)

As far as the wrist thing is concerned,for the Coronal Wristband, I'm assuming they assumed you wouldn't want to wear "gloves" while wearing that, or you wouldn't see the flower and people would complain about that.. hence , most likely , the reason it is a hand slot.

With that said, I haven't dug into 1h vs 2h wands/ staff animations much... so I could be wrong, but this is just a quick guess as to how it could end up like this.