I think that they could make the advanced classes without removing or limiting the base classes. Why not keep, for example, Thaum and Conj as perfectly useable classes. Solo players will require these universal classes anyways. Even if you could move onto an advanced class R30 Conj + R20 Thaum =' White Mage. This would be a specialized healing class. (some of the skills say Requires: Lancer etc anyways, just update the skill to say Requires: Conj or White Mage) This leaves a ton of room for future classes as well. R30 White Mage + R40 Conj ='s White Sorcerer, or even R50 Conj ='s Sorcerer.

The weapons could be unique to the new classes, or they could swap over from other classes. How could they make it a smooth change to select your advance class? It would be easy with unique weapons of course, same system as we have now. But how could they do it with existing weapon types? ...

.....They could have class selection instead of automatically switching when the weapon is equipped. Click Class Selection, It can ask you to select the type of weapon you want to use. If you don't have the proper weapon in your inventory then you can't complete the class change. That would be cool, cause then different classes could use a couple types of weapons.