Not to sound overly defensive of my idea, but technically, it's not that big of an overhaul...

Each on/off switch simply adds a check in the automaton logic: where it would normally have done something, now it doesn't, because you said don't ever do that, or "only do that under these simple/specific circumstances."

On the surface this system resembles, but only scratches the surface of, the Gambit system that I'd have otherwise suggested but is clearly too much to add to FFXI. The AI Card system only adds the most basic of options, with the Drain/Aspir tiers thrown in for a little bit more control, and the ability to select specific maneuvers to trigger specific weaponskills (rather than relying on elements that often have conflicting results between weaponskill selection and attachment effects)

All of these checks already exist, from my understanding, including some other variables the automaton takes into consideration at regular (adjustable) intervals. I don't think it would be too hard to learn how to turn abilities and spells on and off, or to remember which maneuver you selected to trigger a weaponskill.

Also, this suggestion actually requires and allows for the current maneuver control scheme to continue in existence, so it's not a whole new system to learn. My addition simply allows for fine-tuning of the choices open to the AI at certain points.

(I also like how my suggestion opens up future possibilities for the job that are currently impractical to implement due to limited attachment slots and elemental capacities, so it "kills two birds with one stone" in effect.)