I agree with the first point; but generally I could anecdotally never recall a situation of a tank never using mits - interesting note I find too many tanks have a bad habit of waiting till they are 10-20% HP before considering a mit. I notice healers letting tanks dip lower these days now too.
As for the WHM comment the wording I used was terrible; I mean to say if you suddenly added complexity to WHM rotation then it would no longer be the "simple" healer; word limits such but yeah if your going to complicate healer classes then you probably want to leave a summoner esque healer for players to settle into.
To the final point I disagree; I think EX/Expert is to give those lower performing players something to challenge themselves; lets be honest anything below EX/Expert is laughable in difficulty and so I cannot take the player difficulty complaints there in good faith; but I think knowing what buttons to press is a significant difference from understanding a rotation routine for some jobs (admittedly havent played viper yet but have heard its very braindead). I DO agree that for Savage or higher however at that point you should be going outside the game to generally optimize your playstyle; but I think thats just a difference of perspective of where the bar is.
Footnote - I hate the 2 minute window for exactly that reason and admittedly I often see a lot of players not really understanding aligning the 2 minute burst despite the MASSIVE difference it has on a parties success. I am interested to see these forums once Savage comes out tommorrow.