My plan is to use a job boost to make one of my new character a lvl 60 Warrior.

I actually want to play Dark Knight but don't feel like going through the hassle of leveling to 50 just to switch. So i thought i'd boost as a Warrior to begin my adventure as a lvl 30 Dark Knight.

Is it possible? Can the quest to become a DRK be accessed as a boosted character? Or do i also have to pay to complete the main scenario before i can even access the class?

Any complication? Could i start questing at lvl 30 or would i have to rush through the lvl 1-30 main quests first?

Well thanks for the support, i don't want to pay and then ruin my experience, i want to enjoy leveling a bit on a DRK.