Which class? I have never asked that of anyone in the 8 yrs I have been playing.
Same for which spec.
Same for which race.
Which gear is better? Generally the one with more stats.
Stat priority/weights/softcaps? Theorycrafting unneeded to experience 99% of the game. And that 1%? Mythics and rated pvp that take too much of the Dev's attention relative to the number of people overall who play it.
macros/auras? more deep gameplay stuff unneeded in casual play.
Dps meter? see above.
Personally, I pick a spec, and play it to the best of my ability without almost any out-of-game homework. And you can finish 99% of the game doing just that.
Legion is the best xpac yet for people who don't push the bleeding edge of content. As for those who do .... well, you can grind till your eyes bleed to keep up, join us down here in "story mode", or quit, as you prefer.