I'm actually mostly fine with both those changes / reductions, unless they'd be willing to actually make something interesting out of them.
The only thing interesting about MP management was the damage penalty attached to Ballad / Promoted Bishop (lost AoE damage / Rook uptime). It was purely a physical ranged mechanic. At no point did MP existing make Cure I / Benefic / Physick interesting or worthwhile.
Similarly, enmity and enmity combos, due to how straightforward and permanent Enmity works in this game, were never nuanced or interesting. You stacked multipliers, achieving a giant enmity lead early in the fight, dropped stance, and then left it off for the rest of the fight. Enmity combos were even worse, in that they consumed up to 4 keys just for alternatives that you used only under the similarly underutilized tank stance state, to the point that we'd spend 5 buttons on a 20-second stretch of hitting 456 instead of 123. It was bloat.
A context for actual MP management, on the other hand, would probably look something like...
- Hefty MP costs attached to most abilities. %MP restoration removed from abilities outside of Lucid Dreaming (as attaching MPR to abilities only makes it even more costly not to just blow them mindlessly on cooldown). [SIZE="1"]Pure damage abilities would have only negligible cost, as their addition to average ppgcd was just siphoned out of Glare/Broil/Mal/Dos spam anyways, so they need only be balanced around the portion of damage they can still produce during intensive healing, due to being moved to oGCD means of output, relative to other jobs.
- Compensatory flat MP reduction on all other spells (disproportionately benefiting the likes of Cure and offensive spells and hurting the likes of costly AoEs). [SIZE="1"]This adjusts the MP economy such that using the burst of healing provided by abilities
- Slightly curtail the power of AoE heals, such as by splitting a portion of their potency among all wounded allies within their area of effect. [SIZE="1"]This means that fewer spot-healing requirements can be addressed at equal or lower cost by just blandly AoE spamming.
- An undermechanic that mostly prevents outright MP starvation, perhaps sacrificing potency for more than proportionately enhanced MP rate as MP increasingly falls below 50%. For instance, up to 6% more MP but 1% less throughput for each %MP missing, starting from 50%. [300% MPR but 50% potency at 0% MP.] This way we can have a mechanic for which failure is obvious and palpable without literally locking people out of gameplay upon failure.
- Finite means of receiving MP from outside sources that are not simply primarily bottlenecked by their cooldowns (no Stormblood Refresh, etc.).
- Ideally, remove Lucid Dreaming and just add its average effect to base MPR (unless the chance that someone might forget to hit it per minute, its negligible weave cost, and the risk of being PKed immediately after casting it and therefore being screwed for the next minute despite being rezzed are somehow worth its bloat).
Similarly, for enmity to be of any interest, adds would have to be able to spawn relatively frequently with some default, targeted enmity, and/or there'd have to be enmity resets, and/or mob manipulation based on enmity. Ultimately, though, if we were to have alternate combos, I'd still rather see them used for anything other than enmity (such as stagger, active suppression/mitigation, part-break, etc), or for a bit of bonus enmity to just be one of multiple bonuses by which those combos would compete with higher-damage or higher-resource-generation combos.
Esuna, as it's currently implemented, is more one-note than any other way of addressing a given debuff, so I'm honestly glad it's rarely used in its current form. Heal check? Nah, just use that special button that's otherwise wasted bloat.
The only thing I particularly like it for is timed on-debuff-cleanse explosions. In any other case, Esuna's being usable just makes the debuff more dull.
Because it at least has that, though, I'd rather see Esuna expanded in its functionality (just not on what it can be used for without actually changing how it can be used).