The ramping mechanic ritualists used to have (with their more direct spells being augmented by the presence of spirits) is genuinely missing, and it does suck a bit that all that stuff is spread among multiple places rather than consolidated into a single profession like they were with the ritualist, but in the context...it would be quite hard to establish their distinctiveness with other professions having so much of the same stuff.
In general, either way, I would generally see expanding existing professions and fixing the broken stuff as being higher priorities.
Oh, yes, if Defiant wasn't bad enough, let's make even more of the skills available to players useless whenever it really matters, and without warning so that players who aren't in the know try dodging or putting up their barrier and wonder why they're suddenly downed...
Big boss mechanics need to bypass reflect and block mechanics and be balanced around either being dodged or eaten.
What really needs to happen is for more bosses that pressure rather than spike. Blocks and reflects and the like are really powerful versus spikes while other forms of support are useless and, in fact, often counterproductive (because gathering up to support means multiple party members can potentially be hit by an AoE spike). More pressure bosses, however, would allow for more usage of things like healing fields and protection boons to mitigate that pressure. Simply telling players "your toys don't work" isn't the answer.