Cure is very useful in my opinion. It's saved me many times, and I've even been able to finish out a boss fight when my healer died; Sunken Temple 1st boss, healer was killed by Doom with boss at 1/2 health and I self-cured my way through it.
You're never at a loss for MP, shallow though our pool is, because you don't ever need to spam Flash. The MP just sits there, so trade it for some HP from time to time. It's not a lot, but every bit counts and 2 cures from you is roughly 1 Physic or 2/3 a CNJ/WHM Cure.