I cant say i agree with the idea of using earth elemental maneuver to cure slow, but there definitely needs to be a larger revamp to the AI.

Normal order: Enhancing > enfeebles > cure

Damage gauge
1) With damage gauge equipped and no light maneuvers normal priority

With DG + a single light maneuver
2) Prioritizes Enfeeble > Cure if hp is more than 75% (stops enhancing until water maneuver used, this will stop stone skin/haste/phalanx being priorities over cure)
3) Prioritizes Cure > all else if hp is less than 75% (stops silence from being cast when you need a cure)

This still allows for enfeebles and enhancing to be cast and to be controllable.