ok round two of the class concepts:

Bishop: Rooting from the Enforcer and Sentinel classes this job tends to be the most optimized for tanking magically potent monsters and foes, they have the ability to lessen the magical damage taken to allies, and offers slight self healing magics.

Gadgeteer: Capable of creating mechanical pets, this job has a continually changing companion based on the parts you give him, they are also capable of weakening mechanical foes with the use of their superior intellect in that field expertise.

Paladin: Rooting from the Gladiator and Sentinel classes this tanking job focuses on use of shield skill and parry skill to stop a foes attacks, they are capable of taking hits both magical and physical but to a lesser degree than the Defender and Bishop. With the use of ally aiding abilities they can also protect friends from all damage.

Red Mage: Masters of the enfeebling arts, this jobs main role is to weaken the enemy with familiar magics, they can also give slight support in other magical skills as well but not to a great degree.

Puppetmaster: This pet job is accompanied with a Mamet that has a class of his own (with your choosing of course!) The Puppetmaster and his companion can then become an unstoppable duo...for the most part.

Defender: This tanking jobs primary role is to mitigate physical damage, it has very little in terms of self healing abilities by prides itself on being able to directly decrease damage dealt to itself.

Templar: This tanking job has the abilities to generate hate in larger quantities than that of the other tanking jobs, it also has a high HP count as well as having the highest attack of the tanking jobs, although it can only heal itself if the time calls for it.

Berserker: Masters of speed and destruction, this jobs primary focus is to deal out quick damage in turn of accumulating massive amount of hate. However they offer absolutely no defensive abilities, which makes battles short, either in favor of the party...or the enemy.

Hunter: This job gains various bonuses depending on what monster type it is currently fighting, the more unusual the monster the more powerful the bonus.

Elementist: This support job is able to imbue weapons with various elemental attributes for their allies as well as having the ability to provide slight magical damage.

Dancer: This support job uses the art of dance to provide powerful magical effects on allies and foes alike.

Summoner: This job can call forth the mighty Eidolons such as but not limited to: Ifrit, Shiva, Leviathan, Ramuh, Titan, Garuda, Phoenix, Carbuncle, Cait Sith, Diabolos, Fenrir, and more!

Time Mage: Masters of the ebb and flow of time, they can drastically alter the flow of battle by speeding up ally actions or slowing down a foe's. They are also capable of unleashing the powerful Time Spell, Meteor.

Engineer: This job is able to create little sentries that provide various effects for allies and foes alike, for example one such sentry could give an aura of increased attack power to anything within its radius, while another might just bind anyone in its aura.

Blue Mage: Mages that learn from the wild so to speak, this jobs learns abilities and magic from the wild Beasts that roam Eorzea.

Green Mage: A support job that focuses primarily on giving strengthening buffs to party members.

Okay, that covers them all except the Mime, Onion Knight and Scholar (as those were more of joke jobs, and I have no idea how to balance them (Onion Knight and Mime in particular) in a MMO standard)