These are more QoL improvements rather than an overhaul and only addresses issues well into the leveling experience rather than something that would help it as soon as Sastasha.
If you want to do an overhaul, it needs to address things from the ground up, like so
Cost and Cast Time Adjustments:
Cure 2
1k MP -> 700 MP
2s -> 1.5s
Medica
900 MP -> 700 MP
2s -> 1.5s
Medica 2
1k MP -> 900 MP
2s - 1.5s
Cure 3
1500 MP -> 1200 MP
2s -> 1.5s
Regen
500 MP -> 400 MP
Holy
2.5s -> 1.5s
Skill Adjustments:
Aero
Deals wind damage with a potency of 40.
Additional Effect: Wind damage over time
Potency: 20
Duration: 30s
Only one Aero spell-induced damage over time effect per caster can be inflicted upon a single target.
Fluid Aura - Deals Water Damage with a Potency of 200.
Additional Effect: Restore 5% of Maximum MP
Unlock at level 15.
Level 56: Enhanced Fluid Aura. Upgrades into Assize
Protect - Reduces damage taken by a party member or self by 8%
Duration: 8s
Unlock at level 20.
Level 86: Enhanced Protect. Upgrades into Aqua Veil
Stoneskin - Creates a barrier around self or target party member that absorbs damage equivalent to a heal of 300 potency.
Duration: 15s
Unlocks at level 25.
Level 66: Enhanced Stoneskin. Upgrades into Divine Benison
Afflatus Solace
Unlocks at level 30
Afflatus Rapture
Unlocks at level 30
Regen
Aeolus Additional Effect: 10% chance after each tick that the next Aero spell of any grade will add its full damage over time amount to its initial damage and cost no MP
Duration: 40s
Divine Seal - Increases healing magic potency by 10%, while reducing damage taken by self and all party members within a radius of 30 yalms by 5%.
Duration: 20s
Unlock at level 40.
Level 80: Enhanced Divine Seal. Upgrades into Temperance.
Cure 3
6y -> 15y
Graniteskin
Creates a barrier around self and nearby party members that absorbs damage equivalent to a heal of 250 potency.
Duration: 15s
Unlock at level 45.
Level 70: Enhanced Graniteskin. Upgrades into Plenary Indulgence
Aero 2
Deals wind damage with a potency of 40 to target and all enemies nearby it.
Additional Effect: Wind damage over time
Potency: 15
Duration: 30s
Only one Aero spell-induced damage over time effect per caster can be inflicted upon a single target.
Unlocks at level 46.
Medica 2
Aeolus Additional Effect: 3% chance after each tick that the next Aero spell of any grade will add its full damage over time amount to its initial damage and cost no MP
Duration: 40s
Benediction
180s CD -> 120s CD
Asylum
90s CD -> 60s CD
Assize
MP Restore 5% -> 8%
Thin Air
Next 2 actions are executed without MP cost.
Duration: 15s
Maximum Charges: 2
Tetragrammaton
Additional Effect: Grants 1 Lily
Aero 3
Deals wind damage with a potency of 50.
Additional Effect: Wind damage over time
Potency: 40
Duration: 30s
Only one Aero spell-induced damage over time effect per caster can be inflicted upon a single target.
Unlocks at level 62.
Aero 4
Deals wind damage with a potency of 50 to target and all enemies nearby it.
Additional Effect: Wind damage over time
Potency: 30
Duration: 30s
Only one Aero spell-induced damage over time effect per caster can be inflicted upon a single target.
Unlocks at level 62.
Plenary Indulgence
Shield Potency upgraded to 400
Dia 2
Deals unaspected damage with a potency of 60 to target and all enemies nearby it.
Additional Effect: Unaspected damage over time
Potency: 45
Duration: 30s
Unlocks at level 72
Afflatus Misery
900 potency -> 950 potency
Additional Effect: Cleric Stance.
Cleric Stance effect: Increases attack magic potency by 5% for 15s
Liturgy of the Bell
Duration: 15 -> 30s
180s CD -> 120s CD
Upon activation, grant 5 stacks of Liturgy of the Bell and skill changes into Lily's Bloom. Upon using Lily's Bloom, expend a stack of Liturgy to release a 400 potency heal in a 30y radius.
Trait Adjustments:
Freecure
Unlocks at level 28. Upgrades Cure into Cure 2
Aero Mastery
Unlocks at level 62. Upgrades Aero and Aero 2 into Aero 3 and Aero 4
Secret of the Lilies 2
Unlocks at level 68. Restore 5% MP upon use of a Lily
Aero Mastery 2
Unlocks at level 72. Upgrades Aero 3 and Aero 4 into Dia and Dia 2
Enhanced Tetragrammaton
Allows the accumulation of charges for consecutive uses of Tetragrammaton.
Maximum Charges: 2
Unlocks at level 76.