I pretty much agree with everything you wrote with the exception of the bold, if you are referring to the Jarvis hit. Go back and look at the link I posted above with still frames a fraction of a second before the hit and at moment of impact.
EDIT: For convenience, I posted them here instead:
A second before the hit: Elbow tucked
The moment of the hit, elbow tucked and both skates on the ice.
There is head contact, but by the NHL rulebook, it's not an illegal check to the head. The rule states that 1) The head has to be the main point of contact. That's not the case here as he's hitting his shoulder/chest simultaneously. 2) Contact with the head was avoidable. By avoidable the rule says "whether the player attempted to hit squarely through the opponent's body and the head was not "picked" as a result of poor timing, poor angle of approach or unnecessary extension of the body upward or outward". I don't see him "picking" the head here.
So IMO, by the NHL rulebook, this is not an illegal hit.
That's not to say that Trouba's Elbow hasn't come flying up on other hits (or even misses like in the TB series). I even made a joke about him leading with his elbow in the thread about his captaincy. I'm only referring to this specific hit on Jarvis. I do think it falls into the "predatory" category like AA said above.
Anyhow, that's water under the bridge now and deviating from my initial post before the Trouba discussion. Like when Aho got a concussion from Giordano early on in his career, hopefully Jarvis learned a lesson and yet will still be willing to go to the dirty areas like he has been. If he continues to play the way he did, I expect big things from him this yeaLPS?