I sort of agree with what you're saying, but really with practice it boils down to three things.

1. Do I have aetherflow, do I not need to save it? If so, then fester.
2. Keep up dots.
3. Use rouse/spur.

As MMO veterans know, the key to successful consumption and processing of the information the game throws at you is keeping a good "area of focus". Your eyes shouldn't have to move much at all. The area underneath your feet is generally the most important area to focus on, as well as your target's facing.

Idealy, your HUD is setup that your bars, target and self, and cooldown watching, are all very close to each other, near your feet where you should be watching.

Staring at this, its really "1" step to check all these things.

If dots are down, refresh them. My buff bars are right under my debuff target bars, so I can easily glance and check if shadowflare is up. If its not, and the boss won't move, drop that down as well.

Similarly, I have contagion, rouse (you DON'T need spur or enkindle here, as you can just count rouses, spur every 2nd rouse, enkindle every 5th unless you know you ahve to save it) on a hotbar right below my buffs.

Watching your pet position is important, but mostly once you learn a fight it becomes trivial.

I suppose being used to playing WoW locks, this is essentially an afflict lock with no procs, which is monotonous.