I did not read all these pages of posts, but what I personally hope is that you need a certain combination of classes in order to unlock jobs, IE:

Red Mage needs Conjurer 10 and Tham 10
Do a quest once you reach the prereqs
Complete quest and unlock the Red Mage job

Dragoon needs Gladiator 5 and Lancer 15
Do a quest once you reach the prereqs
Complete quest and unlock the Dragoon job

But allow us to have what ever weapon we want on what ever kind of job we want.