I mostly agree with most of the changes asked for here, like AoE Kardia would be neat, Krasis is also kind of underwhelming and is most usually used as another Soteria for strengthening Kardia heals on the tank.

But one thing I absolutely disagree with is damage neutral Toxikon. If you make Toxikon damage neutral, you'd trivialise tank healing much more than it already is. You'd do just as much damage keeping 100% uptime of Eukrasian Diagnosis on the tank as long as you don't overlap it before it breaks. That's like saying that for SCH, if your Adlo breaks, your next Broil IV will do 590 potency and be instant cast. It'll completely break any semblance of healer balance and make SGE the objectively best choice for everything except log runs. Not to mention you'd get 3 x 660 potency hits for every burst window, which would make SGE the undisputed king of damage from the healer role. It would basically be griefing to not lock 1 slot to SGE in regular PF.

However, if you bump up Toxikon to be less of a damage loss, that's completely reasonable. Losing 330 potency for using your movement tool is too much, considering SCH only loses 75 potency if Ruin II is needed.