What I'm suggesting/seeing the viability of is every class being able to equip any job crystal. So a person would be able to be a Paladin Marauder, Warrior Gladiator, or Summoner Conjurer.

I'm not saying I believe this to be "easy" in the sense that SE can simply check off every job being useable for every class. Obviously this would be a semi-large scale change.

It would work in a way similar to how it is now, you level a class to 30, and any job you equip to that class retains the level of the class to which it is equipped.

There's also the issue of lore and stuff, but I'm sure SE can figure it out, you know, given that SE makes the lore... I haven't unlocked every job so I don't know if there will be conflicts with, say, the process of a White Mage unlocking Warrior and being a White Mage Warrior. I don't know how the restrictions to actions would work out. Maybe the three that the job requires at the moment, plus the abilities of the main class?