Ive been playing discipline as an alt since bfa. I never quite enjoy it though. I love the idea of healing trough damage and priests in wow are one of my favorite classes in lore.
The gameplay just doest click 
Setting up ramps feels very unintuitive because it requires so many steps to be efficient. I understand that some like the hectic gameplay but for me it kills the spec.
Why does disc need to spread shields one by one when a mage does it in a single spell. Why does mistweaver passively cover whole raid with hots when disc needs to do it with sweat dripping.
I dont really know how i would change the class but atleast I would get rid of the abysmal atonement appilaction. Would also be nice to have maybe a “power word” that when cast would apply your next spell to 5 allies or enemies. Rapture could be an area effect spell on a low cooldown that would give shield too multiple allies affected.
Maybe its just “skill issue” i dont know. What do you guys think?
Disc and Resto Sham are the only healers I ever manged to play. Disc also has much less keybinds so it is beginner friendly too. Basically you cast penance to empower your shield, and shield your people, and try to avoid casting flash light as much as you can unless you have a proc. In pvp I go Oracle and in PvE I go Voidweaver. You need to practice in order to mange damage-heal gameplay. You also need macro for spells so that you can heal or damage, purge or dispell, if your target is an ally or a target to harm. For example, binded Smite and Flash Light together. If my target is ally it casts heal, if it is an enemy it casts smite. Etc.
OP is talking about raids, where disc is a lot more stressful to play.
Personally Im enjoying disc a lot in m+ and PvP. I wish that they would revert some of the changes in s3 DF, which made it so smite spammy. I really miss old 2 charge mind blast with low cd and harsh discipline along with twilight equilibrium. But overall Im quite happy.
IMO Radiance should apply Atonement on everyone in the raid, just like in M+. That would make Disc way more fun to play.