I really liked this thread, it correlates with alot of ideas I've had about the job system. But the one thing that I dislike about your idea, is that all the advanced jobs until the few at the end are just a combination of two classes.

I'd much rather see more and more advanced jobs that are greater combinations of things.

For example, a red mage wasn't just a mage that could cast white magic as well as black magic, it was a character that could wield swords and melee. (not the ffxi style redmage mind you, the ff1 style redmage.)

So instead of just having rdm be thm and con, I'd like to see it be thm con and gla.

Further more I'd like to see jobs have their own progression. Perhaps replacing physical levels with job levels. The job levels of course would be truncated... and the actual character level would still be based off of the class rank, but the farther you progressed a job the more bonuses and abilities you'd get from that job.

So you could be a CON/RDM and be a Healing aspected red mage with access to nukes, and all the support spells, skills and triats of a rdm.

Or you could be a THM/RDM and be a nuking aspected red mage, with access to healing, and all the support spells, etc.

Or you could be a GLA/RDM and be a solo or small party support class that can melee, can heal, can nuke.

Each class could end up having several jobs that it opens up, and each job would put a different cast on the class, GLA/THF, a rogue style gladiator, more dps than damage reduction. A GLA/PLD, heavy defense, cure spells, and enmity abilities.