As long as crafts are touted as full individual classes of their own, this suggestion doesn't really make sense.
Would it make sense if we apply the above to DoW/DoM classes?
i.e. You can only be master one melee class with 2 advanced melee classes as support. A limit will be placed on the cross-class skills you can use or their effectiveness.

By the way, its "dyeing", not "dying". I don't need extra ways to die.