Though I see some job examples that can be completely omitted from the concept, like Templar/Guard/Sentinel...Templar can easily be a combination of Ronin + Warrior/Warrior+Paladin... Personally, I think the OP needs to try to refine the chart down to something that's more simpler and easier to grasp rather than have something that involves more than 30 jobs/classes. A comfortable zone is 15.

Here's what I think should be done for the advanced job requirements, and how the base system works. First, the nomenclature:

Class - the Disciple of War or Magic, at its very core. (Gladiator, for example)

Core Job (CJ) - The Job that is acquired directly from the Class. (Paladin, for example)

Advanced Job (AJ) - The Job that requires at least two Classes or Jobs at a specific Level.

I'd use the OP's chart, but nearly ALL of the advanced classes do not seem to make sense. (Lancer + Marauder should result in Dark Knight, in my opinion.) So we'll use what I just mentioned: Lancer + Marauder = Dark Knight.

Currently the Level cap in FFXIV is 50. We're getting Jobs in 1.20. So it stands to reason that we will be seeing a level requirement of 50 for the requisite classes before we can do the quests to unlock the Core Jobs. Why? Because, when you think about it, the Core Jobs will NOT require leveling. They already share their required Class level.

However, what about Advanced Classes? Do they also require leveling? My bet is absolutely.

Here's how that would play out: You have two classes at L50, Marauder and Lancer. You leveled them before Jobs came out, and now Jobs have come out, and Advanced Jobs are about to be released. Because Advanced Jobs draw from two classes/jobs to unlock, the Advanced Job can't utilize their levels.

So you have an advanced job at Level 1. So as a Dark Knight that utilizes L50 Lancer and Marauder, you have to go through the grind all over again like a newborn sprat with no diapers.

A caveat to keep in mind is that Square Enix may choose to raise the level cap after the PS3 launch, and that means your Classes and Core Jobs (Ex. Lancer and Dragoon) would need to be leveled again to the cap. And both would have to be leveled separately.