I feel that you guys are being overly cautious with Soraka's rework. Yeah, a safe healer is extremely unfun to play, but she's a support that the current meta is very disapproving of: she is neither an engage support or a disengage support. Her CC is very weak and easy to dodge, and she herself is quite squishy (and is discouraged from building health). Healing is the only thing she provides to the team, and since you guys are doing a great job at making her healing involve danger and interaction with the enemy, it means that Soraka requires a lot of skill that doesn't really correlate with her impact on the game.
From what I've been playing, Soraka excels when her team is self-sufficient. This means that her ADC needs to be safe and/or self-peeling (Ezreal, Caitlyn, maybe Jinx), and the other players need to be able to engage/disengage on their own. If these (extremely rare) conditions are met, Soraka shines brightly, being able to keep her entire team alive throughout an entire teamfight and easily pushing her team towards a great advantage.
However, if these conditions are not met (because most people love to pick very squishy and unsafe champions that require a lot of support babysitting), Soraka's effectiveness compared to other supports falls drastically. She has virtually no peel, engage or pick potential, she can't heal people who are so squishy that they die in one hit, and she can't deal with high-damage, dive-heavy comps. She also struggles when her entire team is made of squishies (Riven top, Yi jungle, Lucian ADC and Zed mid, for example, your typical soloqueue comp) and she can't figure out who is the highest priority target to heal.
To be honest, I feel Soraka needs the W range buff, but she cannot afford any more nerfs. In fact, I'd say that 50 units of W casting, while very welcome, will not solve any of the above problems. She needs to be so good at what she does that she can actually compete with supports that offer heavy CC on top of utility, such as Morgana, Nami, Sona, Thresh, Janna and Leona. If you guys don't want to give her reliable hard CC or tankiness, that's fine, but she definitely needs more than what she already has in order to be a viable competitive pick. While the other supports I mentioned fit into any teamcomp, the fact that Soraka needs a specific teamcomp tailored after her indicates that she's not in a strong place right now.