I agree with most of your post however their is one thing I feel the need to point out since the picture painted isn't exactly complete in regards to crowd control.
Crowd Control is not limited to just the damage dealers, though traditionally gets assigned to them simply because they actually have the fewest things to be concerned with. Not that their role is any more difficult, but fundamentally the tank is always concerned with all targets that are free. The healer is concerned with all members of the party. The damage dealer can afford to be concerned about controling one or more targets while dealing damage to their primary target. A Druid tank, can use crowd control as well such as Hibernating on the pull, using Entangling Roots before the targets reach them with the glyphed instant cast version, as well as use Nature's Grasp while in bear form to root up to three additional mobs while moving out of their melee range. A Feral Druid tank could effectively crowd control five mobs on the pull. While they don't have the advantage of being able to renew their crowd control mid fight pull this does not exempt them from potentially needing to do that function, and even if it only buys a little time it is still less damage taken overall. The healer as well can do crowd control. How many times have you had a Holy or Discipline Priest use Shackle Undead, or a Restoration Shaman use Hex and/or Bind Elemental, or a Restoration Druid use Hibernate and/or Entangling Roots? Generally speaking the tank or healer won't do the crowd control because sharing balancing the workload and the number of things each individual is responsible for would tend to leave this job to the damage dealers.
The job of avoiding and reducing damage taken falls on everyone in the group. Regardless of if your little icon is a sword, a shield, or a little plus sign. Crowd control is one of the means of reducing incoming damage. It is cheaper for a healer to cast a single Hex, Roots, ect. than it is for them to cast 5 extra heals on the tank because the target was attacking the entire time.
"In anything, if you want to go from just a beginner to a pro, you need a montage." /w TankSpot WTB Montage for Raiders.