I totally agree about this Draco and his relationship with this Harry. It keeps coming back to me that Draco has grown up receiving punishments on Harry's behalf. That has surely shaped the way they feel about each other. It is part of Draco's programming to be loyal to Harry, but that doesn't add up to a relaxed, fun friendship.

And it seems to me that we've seen signals already that Draco is jealous of Ron. I fully expect that tension to grow over time. Ron and Harry have fun exchanges -- in part because Ron did not grow up being taught to defer to Harry as a princeling. (And Harry gets prickly with students who seem awestruck by him -- he nearly took Hannah's head off, I think -- so I can see why Ron's unfussed response to him would be so appealing to Harry.)

I'm intrigued, too, by Draco's report that Madam Pomfrey told him he needs to fret less: I think this Draco is pretty tightly wound. (That strikes me as canonical, too.) We've already seen that he worries about measuring up to his father's expectations, that he's programmed to be anxious about getting in trouble (and about being held accountable if Harry gets in trouble), and that he worries that something bad might happen to his father (Draco was angriest with Pansy when Lucius let slip that he was taking heat for Pansy's behavior). I expect to see Draco put under increasing pressure as this game moves forward, and I expect it will take a measurable toll on him.