Originally Posted by
Apoptosis99
No Heroes: Yeah, that's not in. Though, I could see developers shy away from this since programming a sophisticated AI would be difficult and resource consuming (not a programmer, so I'm guessing).
Killing a boss to capture elite skills: There are skill challenges all over the world in GW2 (I think there are over 250 challenges). Sometimes you have to kill an elite mob to get the skill point.
Instanced missions: While dynamic events are all open, there is the personal story missions which are instanced. You can bring friends along with you if you party up, but you don't have to.
Vanquishes: I don't know what that is, since i haven't played GW1.