I looked up the game on Youtube and saw an original demo playthrough with Punky: all my moves have recoil, Jeldritch, Rover, Glarp, Voodude, Leafy, Frump, Mantex, Sprout, and Mush.
Jeldritch and Mush look really cool. And that Suspicious Goo makes me think some Xenos will have branching evolution: one by level-up and another by item.
Enemy AI will use Heal moves even if they're at full/barely damaged. You can see with how Voodude kept using Cauterize.
I think the way healing is balanced is pretty good. Just that Nap needs to cost more since it's leagues better than the rest. Full heal + curing status (for just 6 MP) means it invalidates multiple actions' worth of MP.
Regeneration is 25% HP per turn, 1-4 turns, for 6 MP. Incredibly efficient considering Heal is 25% for 4 MP. You "lose" if it's only 1 turn, but win if it's longer by a mile (up to 16 MP worth).
Gaia Burst is technically a healing move... if you survive. Though it's only a finisher move and even for enemy use it would fall off after early game. A boss with Gaia Burst would just heal you after you have defenses to survive.
I do think bosses with stall/debuff/DoT strategies would make sure your team isn't just brute force. Life drain attacks would fall off against high defenses or blind/accuracy reduction.
The issue that Poison/Burn to beat bosses is you just need to inflict them once and just survive because it ticks off 10% their HP every turn. Immunity just removes options, resistance makes it harder to stick. The best solution would be options to cure status without cure-all like Nap.
Psychic Screech: 6 MP. Deals medium energy damage. Cures Loony status; inflict Loony on enemy.
Shocking Grasp: 8 MP. Deals medium energy damage. Cures Paralysis status; inflict Paralysis on enemy.
Noxious Gift: 6 MP. Deals medium energy damage. Cures Poison status; inflict Poison on enemy.
Tranquil Mind: 6 MP. Heal 25% HP, cure Blind/Loony status.
Holy Water: 6 MP. Heal 25% HP, cure Poison/Delayed status.
Nature's Blessing: 6 MP. Heal 25% HP, cure Burn/Paralysis status.
Purification Ritual: 8 MP. Due to your body feeling weak from expelling all maladies within it, permanently increase damage taken by user by +10% (+10% for each additional use) until the end of the battle (Brittle status; cannot be cured). Cure all status.
Burning Spirit: 6 MP. For 4 turns, gain a Shield that absorbs 5% max HP damage per turn (refreshes each turn). Gain 1 stack of Burn resistance; cure yourself immediately if Burned, then remove 1 stack. Cannot be used if already Shielded.
Assassinate: 7 MP. Deal high physical damage. Ignore enemy's positive defense buffs and shield.