Not sure why you're so worried about MP. We're not white mages, we can be lot more generous when it comes to healing. Sure if you sit there spamming Adloquium and Succor you'll run out quickly, but that's why those aren't our only two spells. I can easily keep up Succor up most of the time against Titan as long as I'm using Aetherflow on cooldown and tossing the occasional Energy Drain if I run low. I usually use Adloquium on the tank if two or more people took damage so I can buy myself a little more time to heal them, or if a big hit is coming. Normal Physick and Embrace are just fine, which you should always be casting, specifically Embrace since it costs no MP.