There's a lot more nuances between addersgall and aetherflow that doesn't make them the same. Functionally, they are similar, especially post-lv 80, but for lv 73 and under, due to resource generation, they should be fairly different.
Correct me if I'm wrong, but you're not goanna be generating addersgall from the getgo unless during combat. For example - dungeons between pulls - aetherflow skill gets to be recharged while sitting on cd even outside of combat, but you just can't use it to refresh aetherflow immediately yet. Addersgall doesn't charge outside of combat, it just stays uncharged. Just this alone will drastically change the number of addersgall you get. Keep in mind, we're not a WHM who has the 7 sec stun component in their AoE, so we'll be spending more addersgall in leveling dungeons unless leveling dungeon mobs hits like a wet noodle (which is generally not the case, usually only capstone mobs hit like a wet noodle from ilvl differences). Think Bardam's Mettle + Doma Castle + Castrum Albania + Holminister Switch, except you don't get your first Excog until 20 seconds later. The difference in having your "excog equivalent" / Taurochole be applied at different times will drastically change when the next cooldown of your "Excog" will come back up since Taurochole is up-front heal + mitigation, not a delayed heal. By the time your next "excog" is up, you'd must have been in combat for 65 seconds minimum whereas SCH can immediately reapply Excog within ~47 secs even if it doesn't take into effect immediately. Not a "huge" difference, but a delay of 18 seconds is pretty huge.
While most content gets outdated at higher levels, if you ever choose to sync EX fights or do Lv 70 Ultimate fights, it's also still something to keep in mind. Granted though, having a 1.5 sec cast time should enable you to use your oGCDs better, so it's not that big of an issue.
The other thing you have to keep in mind is that the next time you reapply Excog, it will also have ~45 sec duration before activating/expiring, whereas Taurochole's heal is instant, so if you run into a situation where your tank recovers full HP (between pulls or regens ticked), Excog will always get value after a certain amount of time in combat when it pops, whereas Taurochole won't until it's used up (which, when done in succession, can delay your next Taurochole's usage significantly thanks to cooldown restrictions and not having it on a 2-charge system).
Rizomata vs Recitation
One thing to note about Rizomata vs Recitation too - Rizomata generates an addersgall. That means it's a permanent resource return. You don't have to consume it immediately, unlike recitation which has a set duration of time before the skill expires. While Recitation guarantees Crit HP recovery, Rizomata just has a lot more flexibility since you can also use it for soil or wait until you have to expend more resources later. Basically, it's always a net-MP gain on cd.
Kerachole vs Sacred Soil:
From what I understand, Kerachole and Sacred Soil function the same, but the difference is placement flexibility. Whereas Kerachole is activated around you and within a 15 yalm range, anyone who is outside of your range will not receive the buff after the activation. Sacred Soil has a larger range when placing down, can be set to the ground in a bubble, has a smaller effective radius, and the effects last on everyone provided they are inside the bubble. It's like the AST Collective Unconscious snapshot regen vs Asylum thing, where one activates immediately and isn't worth channeling, whereas the other requires more positioning.
One thing to note is if there's a very movement heavy mechanic where you have to reposition because your parties are spread to 2 sides and have to group back up after, Sacred Soil is easier to place and let the team know where to reposition. If it's a double stack marker for each healer, Kerachole might win here because the extra effective radius can hit all party members whereas a Sacred Soil may not. If anything, you can think of Kerachole as a better Collective Unconscious snapshot.
Fey Blessing vs Holos (lol)
The only advantage to Fey Blessing is that it's centered on the Fairy and can be used to AoE heal from afar and not directly centered on you. Assuming pet potency & stat scaling still not working on the fairy, it's basically a weaker heal for more range. The healing isn't really much anyway, so it's meh. Both skills have fairly moot usage, but 1.5 sec cast time means free heals nonetheless....
Dyskrasia and Eukrasia have potential to do so much more
What I didn't understand is why Dyskrasia couldn't be our DPS alternative to Eukrasia. Eukrasia changes skills by supercharging healing mode. Dyskrasia changes skills by supercharging DPS mode.
Dyskrasia -> Prognosis = Dyskrasia Prognosis (AoE attack)
Dyskrasia -> Toxicon = Dyskrasia Toxicon (AoE DoT attack under addersting)
Dyskrasia -> Dosis = Dyskrasia Dosis (Single Target DoT attack)
Eukrasia -> Dosis = Eukrasia Dosis (Slightly higher MP cost than Dosis, but generates slightly more healing on Kardion target)
Eukrasia -> Diagnosis = Eukrasia Diagnosis ( Single Target Barrier heal)
Eukrasia -> Prognosis = Eukrasia Prognosis ( AoE Barrier heal)