The one thing I like about some sort of reagent based magic class is the implications for the economy. It gives DoL and DoH items that would need replenishing constantly.
Yay! More chores...
If all this class had access to was enfeebles, why not just bring a RDM? We've come full circle to the 'Give my class/job an identity' argument.
But they are bringing back Red mage...
And I think the war on class/job identity has already been won. Classes and jobs have distinct identities now. Blending has been limited in classes, so that tanks are tanks, dds are dds, and mages are mages. But Jobs are very clear cut, No one can out perform any job on it's designed task. While DDs, Mages, and Tank classes can overlap (the difference between an arc, lnc, and pug is pretty much damage type), but the difference between Drg, Brd, and Mnk is quite significant in what they can and can not do.
If they had a mage class that used items to cast rather than spells, and say the spells were mostly enfeebs, you then add Red Mage in the mix, and you still have two distinctive classes, with a significant overlap. Add job specific abilities (be it weaponskills and/or unique abilities only they have, such as Red Mage as a Job is the only one that has spike spells, and Ninja as a job is the only one to have haste or say an enmity reset ability), you would have similar classes, but with a distinction that would allow players who like one over the other to feel different, and allow for different situations to favor one or the other without preventing one from replacing the other for personal preference. Obviously the elitist mentality would require that one be deemed better then another, but, that is an unfortunate, and expected reaction from the players.
But, then again, this is really more of a pipe dream.
We will see how they handle Red Mage soon, and hopefully Ninja and Samurai will follow at some point...