You're all absolutely right. Been looking at my Warlock casting (with AOE disabled) on a Dummy and it's not reacting to auras at all. It's only casting Chaos Bolt until it's under the Burning Ember limit. I'm guessing it's a relatively quick fix for Millz once he's back.
Personally, I've not encountered any stuttering/pausing, but I did notice the excessive spamming once I enabled AoE, for Dark Soul/Berserking for example you'll notice the entry gets written with as many attackable units are in range of you. If you have 3 units in range, it'll spam the window 3 times.
I've done my tests in Silvermoon and not Shrine of Lag.
I also tested Demonology for good measure and it seems to be doing OK? In my tests starting with 200 fury it's doing everything properly. Popping into Meta and applying Doom right after Cor/1st Hog, casting ToC 2 times before coming out and double stacking HoG. I don't see any excessive Meta changing besides those lucky times where you just get out of Meta and everything procs and it tries to be in Meta as much as possible.
I'm easily doing 17-18k DPS single-target after the nerfs with little movement. (Around 25-26k-ish AoE)