Haha... yes. This is funny looking back. It probably took me 40-60 hours of play before I hit 10 (granted I was doing missions and quests a lot along the way) and I was leveling subless BLM. I didn't know how masochistic of a thing that was at the time.

I managed to take most of the rest of my jobs through the dunes in only a few hours. There are just tricks to make it work faster where you break all of the subjob rules.

For instance:
Melee/WHM and use pie
Mage/WAR or MNK and use attack food and high DPS weapons (not stat wands)

You can absolutely fly through those levels like that.