To be fair, we all agree BM hunter is the most braindead class that can be played blindfolded. Buuut, what you’re saying about warrior is applicable to FDK. Yes, the skill floor/ceiling obviously comes into play, as it does with every spec. FDK is still incredibly simple.
I think all classes are super simple, just gotta check guides to see what you’re missing, I would say play what you like. I personally find melee rotations easier to perform during a raid because you can move while doing them but I also haven’t raided since Castle Nathria, so things might have changed.
My alt runs Obliteration. Still pretty simple, but I have very good WA cues to prompt me on what to do when (custom made and custom to my input device layouts).
It really depends on what you mean by acceptable dps. Most dps specs require some amount of forethought in order to perform well in an encounter. Even the most simplistic dps specs have some level of setup or preplanning in order to make use of their cooldowns effectively.
I tend to think that Fury Warrior and Marks hunter fall on the simpler side of things. But what I find simple might not be what you find simple.
Your best bet will likely be to just try out a few specs and see what you most enjoy.
There isn’t a class in game that’s hard to play. I don’t think it’s reasonable to be able to instantly understand a class, either. It feels good to put effort in and get good; Having many choices to make is a good thing! A good class for you would be balance druid, fury warrior, or perhaps beast master hunter!
Just switch your druid to Balance.
Balance is usually in a good spot for Mythic +.
And if you don’t like it, can just switch back and forth between Balance and Resto.
A lot of carry over abilities if you’re used to Druid anyways.
Second ret paladin. You can more or less spam 3 buttons at the same time for the majority of your rotation, or if you get really fancy tap them like you’re tapping your fingers in a line on a table so you’re hitting the better priority ability first just in case it’s up