Archer > Bard(Support), Ranger(Spike damage, glass cannon with enmity shed, maybe use "Great Bows"?)
Pugilist > Monk(DPS, combos), Dancer(TP-based heals and support, bladed H2H)
Marauder > Warrior(DPS, tank), Beastmaster(Pet class, allow one-handed axes? Maybe use different jugs to work with Call Beast for different pets)
Gladiator > Paladin(Tank, support), Blue Mage(Specialize in curved swords and light shields, gain "Learn" at unlock and further use of combo JA for spells and elemental WS)
Thaumaturge > Black Mage(Magic DPS), Time Mage(Support/Enfeebler, use 1H THM weapons mainly, perhaps a "sub" weapon called time pieces?)
Conjurer > White Mage(Heals, support), Oracle(Magic DPS/enfeeble, BLM gets Thunder/Fire/Bliz potency, give ORA Wind/Water/Stone)
Musketeer > Corsair(Luck based support/DPS), Engineer(Aim abilities like Tactics but give it a pet, think PUP hybrid sorta)
Arcanist > Summoner(Pets, yadayada), Scholar(Sub CNJ/THM, use "Helix" JA combo'd with a spell to activate Cryohelix, Pyrohelix, etc, same with say, Storm spells)
Squire(Great sword) > Dark Knight(Strong DPS, enfeeble), Samurai(GS sub-cat: Great Katana, single target sub-tank, combo specialty)
Fencer(Fencing sword) > Red Mage(Enfeeble/Support, usage of "Spikes" and "Enspell" JAs combine with CNJ/THM spells for various effects), Geomancer( Sets traps and uses various elements to inflict damage and cripple)
Rogue(Dual blades) > Thief(Enmity control/Spike DPS), Ninja(Enfeeble, Combos, sub-cat of blades... kunai?)