I don't really think it's something that needs to be removed. But if it ever were, here's how I would handle it for SMN and RDM:
SMN
Spell: Resurrection
Cast time: 8s
Recast time: 2.5s
Resurrects target to a weakened state.
※ The cast time of this action cannot be reduced by the effects of Spell Speed or Swiftcast.
Trait: Resurrection Mastery
Grants the effect of Phoenix's Favor after using Aethercharge.
Phoenix's Favor effect: Upgrades Resurrection to Rebirth.
Spell: Rebirth
Cast time: Instant
Recast time: 30s
Resurrects target to a weakened state.
Can only be used under the effect of Phoenix's Favor.
RDM
Spell: Verraise
Cast time: 10s
Recast time: 2.5s
Resurrects target to a weakened state.
※ The cast time of this action cannot be reduced by the effects of Spell Speed, Swiftcast, or Dualcast.
Trait: Verraise Mastery
Grants the effect of Chain Raise after successfully completing a combo with Enchanted Redoublement or after three successful consecutive uses of Enchanted Moulinet.
Maximum Stacks: 3
Chain Raise effect: Upgrades Verraise to Verraise II.
Spell: Verraise II
Cast time: 2.0s
Recast time: 2.5s
Resurrects target to a weakened state.
Can only be used under the effect of Chain Raise.
The cast time of this action is affected by Spell Speed, Swiftcast, and Dualcast as normal.
This would restrict SMN to a single instant raise per minute and RDM up to three instant raises which would then take about two minutes to replenish completely. It would still allow either job to slowcast raise when out of charges, and this is probably okay in most cases as it's just the rapid Dualcast raises that are of greatest concern.
BLM changes would be a bit more involved, however.
BLM
- Ice spells are always free.
- While not under the effect of Astral Fire: all spells are free.
- While under the effect of Astral Fire: Fire, Lightning, and Paradox spells cost Umbral Sparks.
- Firestarter and Thundercloud reduce the costs of their corresponding spells to 0.
- Umbral Hearts reduce the cost of Fire spells by half.
- Umbral Sparks replenish at a rate of 3 per Umbral Ice stack per tick, up to a maximum of 12.
- While not under the effect of either elemental aspect, Umbral Sparks replenish at a rate of 1 per tick.
- Manafont restores 4 Umbral Sparks.
Umbral Sparks costs of spells under the effect of Astral Fire:
- Fire: 2
- (High) Fire II: 3
- Fire III: 4
- Fire IV: 2
- Flare/Despair: All, minimum 1
- Flare with Umbral Heart: All but 1, minimum 1
- Thunder I/III: 1
- Thunder II/IV: 2
- Paradox: 2
This would leave BLM largely unchanged in functionality...but if the goal is to remove MP just to have things still work the same, why remove MP in the first place?