Soraka Changes are an Overall Nerf
As a Soraka main I just wanted to give my opinion on the upcoming changes.
E-max will no longer be a choice. The reduce CD of E is redundant. The damage and mana cost nerf will make you not want to max this anymore. This was the primary choice in majority of my games because it's much harder to hit a Q past level 3 against competent enemies.
You would think they would buff Q's damage or projectile speed/range. Instead Q damage is nerfed, while the CD is increased. They changed how the MS works. Although it decays, and you won't have the damage/CD anymore to pressure the enemy with followup Q's.
Overall, Q is flat out nerfed, E is flat out nerfed. The only buff is allies will have the Q's heal part frontloaded, along with a decaying MS boost. These changes will make Soraka more reliant on her ADC, and won't allow her to attempt to poke out tanks. While she'll be better at sustaining poke lanes if they get hit by a Q.
I think Q's CD/Damage should remain the same if they want to nerf E max that heavily. I much more prefer the current Soraka's playstyle of how she can individually impact the lane to scale herself successfully to mid game, even if the ADC was bad.