- You dont need to meld piety for O8s, I dont have and unless I have to rezz a lot of ppl, I don't run into mana issues. Just keep in mind to extend Lucid Dreaming with Celestial Opposition (its also nice to extend aoe cards, Cleric Stance and pots with it).
- For role skills I use: Cleric Stance, Lucid Dreaming, Swiftcast, Largesse and Surecast. Might change Surecast for fights where you I don't need it.
- Use Aspected when a lot of Aoe damage is incoming. You can also place the star beforehand so you don't have to manualy heal afterwards. Unless my co-healer is dead, I barerly (maybe never) use normal Helios, except for the God Kefka fight.
And don't worry about your healing being low. It doesn't matter, if nobody dies it's just fine. Why waste your time with overhealing? The interesting part about healing is to find out how little you can heal without your team dying

(I play Noct Ast most of the time)