I'll repeat some of the stuff I've written about before:
Fencer: Red Mage (DPS), Mystic Knight (tank)
Musketeer: Gunner (DPS), Chemist (healer)
Rogue/Scout: Thief (DPS), Ninja (DPS)
Astrologist: Time Mage (DPS), Green Mage (healer)
On Beastmaster:
I don't see it working as a class. It really doesn't give room for branching. Not to mention that I'm sure BST fans would be mad about their job of ages past being a class that'll get obsoleted out when job crystals enter the picture.
Off the top of my head, a Barbarian class would probably work better.
Basing barbarian off totems (maybe 5 totems in total at 50) and having them focus on one-handed or even dual axes would then give room for the following:Barbarian: The northern wilderlands boast of many great dangers, and braving these from day to day is an isolated tribe of savages. Confirmed to being outside of the influence of The Twelve, these nomads honor animal totems that give their warriors strength and their leaders wisdom in times of need. Those accepted into their fold are eventually taught the secrets of drawing power from totems.
Beastmaster: Focus on combat with a pet joining in, with the five totems being replaced with slots for five pets of your choice (lore you could say is that forsaking the buffs of the totems, a Beastmaster instead does a spiritbond thing with an animal to get its help).
Feral Youth (can't think of a good name): Enhanced animal totems with additional bonuses, lore explanation being that in addition to taking on a blessing from the animal totems the Feral Youth also takes on aspects of the animal they were blessed by.