It really depends on what those buttons do though. For example:

Stone III/Glare III - Deals 350 potency damage to a single target. Generates 10 Earth gauge. 70% chance to enhance Stone IV/Glare IV.
Stone IV/Glare IV - Deals 200 potency damage in an AoE. When enhanced, potency is doubled. Generates 10 Earth gauge.
Aero III/Dia III - Deals 350 potency damage to a single target. Generates 10 Wind gauge. 70% chance to enhance Aero IV/Dia IV.
Aero IV/Dia IV - Deals 200 potency damage in an AoE. When enhanced, potency is doubled. Generates 10 Wind gauge.
Water III/Tempest III - Deals 350 potency damage to a single target. Generates 10 Water gauge. 70% chance to enhance Water IV/Tempest IV.
Water IV/Tempest IV - Deals 200 potency damage in an AoE. When enhanced, potency is doubled. Generates 10 Water gauge.
Holy III - Deals 500 potency damage in an AoE. Costs 20 Earth, Wind, and Water gauge.
Afflatus Misery - Deals 1400 potency damage in an AoE with falloff damage. Costs 1 Blood Lily.
Assize - OGCD deals 300 potency damage in an AoE, restores 5% of your MP, and heals with a potency of 300. 40 second cooldown.
Presence of Mind - OGCD Reduces own cast and recast timers by 20%. 120 second cooldown.

That's 10 DPS buttons, but it's not necessarily all that complicated. Not saying budget Red Mage is the way to go, but just using this as an example. I think trying to set a quota of what you want to achieve can give you framework to guide you on some level, but the quota itself doesn't really matter. It's what you do with those actions that matter.