I can see this system working but I would prefer it would be within one unit of a job, and like FFXI (oh no dirty words lol) make a special system for Blue Mage (slotting system).

Like for Blue Mage I hope they don't get stuck in their class and job structure, trying to make everything fit when it could benefit greatly being 'different' (as much as I like keeping systems neat and tidy, I see SE's current system verging impossible for certain Jobs people want - without making special exceptions).

Still, your system could work.. so no hate here - just my preference for the Blue Mage to be contained within one unit :P