If I replaced the word "Base Classes" with "<Weapon> User" and kept the name "Advanced Classes" or used "Job" for the traditional FF classes. What I've laid out would still work with no other changes because it's the same thing.

The point I'm trying to make is that it doesn't matter what they call it. As long as players can relate to it they will approach it.

I like the idea Kaze and your post is extremely well thought out and organized. The skill tree maybe a bit overused in mmo's but how else would you organize it? I'd be willing to have these classes back to have stradegy and class uniqueness. Of course adding the extra classes will be awsome too like Bard/Dancer or Summoner/Blue Mage.

Now for something else I thought of they would need a starting class based on the skill trees you presented so I was thinking something like this....

Entertainer > adv. job Bard/Dancer = Would participate in a variety of musical or entertainment quest and use musical insturments and daggers or knuckles as their arms.
What I was trying to avoid was getting rid of disciplines and putting them on certain paths. If I take your suggestion and put it along with mine I would give PUG the option to go become a DNC. Instead of starting a new base, Entertainer in your case, and going from there.

Either route needs lore attached to it; but I think my approach requires less and can be built on top.