I'm just gonna drop my final thoughts on how the vanity slots should work here. People who agree can like it, and people who don't can go typing away.
I know I agreed with the toggle option earlier, but if the system is implemented well the toggle option is better off not being there... since it really does directly oppose the existence of the vanity slots: to separate how your character looks from how well he/she is geared.
As for how the vanity slots should work without a toggle option:
- They should be limited by the same class/job/level requirements as the primary slots
- Seasonal event items (reindeer, dream, etc.) cannot be equipped on vanity slots.
Considering the lenient requirements for class/job on most crafted gear, and the existence of recommended level gear, which work perfectly fine as vanity, this won't be very limiting at all but at the same time not completely destroy the feeling of the game.