Well Riptide is being used frequently but I can’t tell how many people you have them on, which isn’t super important due to the added riptides from our 4pc.
Healing Stream Totem looks fine too, although varies a bit from fight to fight in the frequency of being cast.
Elemental Blast is definitely on the lower end, although you have to look at your mana throughout the fight and determine whether or not the additional casts would be worth it to gain more mana. Should you come to the conclusion that you actually don’t need the mana from it, you should swap it with Primal Elementalist for increased output. Can see that you only had 4 casts of Elemental Blast on Kormrok so something to consider, where no potion was used as well -> Drop EB pick up PE and power cd’s more and maybe use intellect potion during that (if not mana is needed).
On Kormrok you’re not using Healing Rain at all. Yes the fight does not favor it but still consider pre-casting it before Grasping Hands occur, adds some more healing. When looking at your mana curves for this fight in particular I can see that there is plenty of room to be more aggressive and spend more mana. You even end the encounter sitting on 30% mana left. You could easily throw more Chain Heals, drop Elemental Blast all together for PE or swap your weapon enchant for mastery (Mark of Bleeding Hollow).
For Council you should try to keep Healing Rain down almost throughout the fight, the group will be stacked nearly 100% of the time and you rarely reposition, this is optimal for using healing rain. Mana on this fight is depleted completely when the fight ends, and here you’re right that casting Elemental Blast more frequently would be beneficial.
From the footage I can see that you’re using Unleash Life a lot when stationary, which isn’t really optimal. The spell should only be used when you have to move, outside of that every other heal we have has higher priority/value to cast.
Spiritwalker’s Grace is not being used, which surprised me if you don’t feel the need to pop it at any time during either Kormrok (4:17) or High Council (6:30). I can imagine several times where it would add more quality with the option of moving while casting. Or as you click the warlock portal in the video you could’ve popped Spiritwalker’s Grace and thrown some heals while moving back to the group. (Although avoiding the portal would be preferred)
Echo of the Elements is a thing of the past, it will give you additional charges, maybe adding a bit more flow/easing into utilizing riptides properly. Although I would recommend going Ancestral Swiftness because the 5% additional haste will make the class feel a bit more fluid and the occasional instant cast has a lot of uses. Either use it to plan ahead (dropping healing rain ahead of the group when moving) or to snipe an incoming hit (Chain Heal on Grasping Hands Kromrok).
In my opinion you should consider benching a healer or two on some fights, Kormrok is easily solo-healed by now and it is possible to two-heal High Council with a proper setup (Dispell charges). Will definitely help on the cooldown situation as well, not being 4 healers to ‘pad’ the entire raid will display more clearly when to pop a cooldown. When overhealing content this kinda blurs out and they become redundant due to healers having too much strength standing alone. More experience will also help!
Then on a more personal matter I feel that you have a lot of clutter on your screen, 3 bars to display your mana and 2 bars to display health and cast. Then I would maybe remove the scrolling numbers to the sides, how important is it for you to know that Healing Rain healed x targets for y amounts of healing? (My opinion ofc) The same goes for the information scroll on the top. And then the bars over your player frame displaying buffs, to me it’s a nuisance.
Sorry for the rant on your UI xD