I believe the best solution is a compromise that has been mentioned in several other threads on this subject.

Basically, make "auto-action" a setting that can be toggled on or off, and that can be configured to use any action that the character currently knows ... be it Light Slash, Levinbolt, Guard, or Cure. The cooldown for the abilities would determine the rate that they triggger, and naturally if you don't have enough Stamina, MP, HP, or TP to pay the cost the ability will not trigger.

Those who do not want to use it, do not have to use it. Those that do, can.