As a healer main my 2 biggest "wishlist" changes to the role are:

1. Make the healers truly unique/less homogenization. Give healers tools that others don't have. You should feel like as a WHM/SCH/AST you bring something unique to a party, not just basically the same spells with different animations.
2. Give healers more DPS abilities or a DPS rotation. Healers right now just use 1 DoT then spam their 1 damage spell over and over. We all know it, and it gets dull. If we got even just 2 more damage abilities it would drastically make the DPS downtime much more enjoyable.