http://ffxivrealm.com/guides/job-class-system-explained.6/
Voici un quote qui a fait ma journée:
"A player may un-equip a soul crystal at any time to return to their base class, thus regaining their cross class slots and having access to more cross-class skills but they lose access to their specialized Job-only skills. It should also be noted that some equipment is restricted to certain jobs."
Donc tu peux essayer toute les jobs au final si t'es pas heureux dans ton premier choix.
:D