Create level 30 class quest, to gain class stone. Not job stone, but to further your training in your base class. Give it the stats boost of the Job stone, but do it similar to the crafters with [class] "Specialist." So, an Arcanist Specialist would focus in Carbuncles, a Conjurer specialist would focus more on the elements instead of the Holy nature of WHM, a Gladiator specialist would focus on raw martial prowess, not the healing and support of PLD. And give us all new abilities to go along with the new focus of the class. Create a system where we have a ton of classes of all types, and lock your level to 30, unless you have your specialist, or Job stone equipped.