So, some initial thoughts, in no particular order.
Ed and Harry have a lot of crappy things to answer for (that scene where they're talking about profiting and swimming in women because of the girl's death (while standing in the bloodstain where she died, and her mother hearing it)), but I don't think blaming Ed for the deaths is actually fair. His Thinman story got used as cover, and those two guys were getting pretty deep into seeing themselves as Thinman, but they were the ones who decided to murder people. Ed didn't encourage or incite them, so I don't think he's any more responsible for their murders than anyone who works on spn would be if someone dressed up like Azazel and killed people. Other stuff yeah, but there's no need to muddy up the situation.
I need to think more about the 'they're just people' part. I think there might be a reading of that that speaks to how you can't just blame supernatural things and leave it at that. Humans are capable of terrible things, and you can't act like bad stuff only come from supernatural sources. It's an odd time for that, because witches are human and they've had witches on the show for a long time now, but maybe it could lead to exploring how much of supernaturally-influenced actions are from the supernatural part and how much from the plain old human part (I'm thinking Sam and the demon blood, here. How much is he thinking of his bad choices as something driven by a supernatural taint, and how much does he see as stemming from his own human motivations? Because in season 8 I got the feeling that he thought purifying himself of the demon blood would cleanse all of him).
Dean is really pissed at people faking at being something more than they are. First it's the Ghostfacers thinking they're competent professionals, then it's the guys trying to say they're the real Thinman. It seems like he sees it as playacting, which I think he would find deeply insulting, not only to him as a hunter, but to all the other hunters and victims who've been ripped apart by the supernatural. But I wonder if there could be a more general theme behind it (or that could be read into it, I don't really want to make the claim that it's intentional by the writers).
Given the above, I'm not as bothered by Dean killing the waiter as perhaps I should be. The pettier side of me thought that if that guy really wanted to be a supernatural monster so badly— if that was a status he eagerly claimed and insisted on— then, well, he was treated in line with that. Supernatural creatures who kill humans (unless there's the rare self-defense claim) are treated as fair game for hunters in this show.
I always figured Dean would have pictured the empty rocking chair as his, not really because of any falling out, but because he's always thought he'd die young. See: Trial and Error, that season 4 episode with the magicians, I'm sure there are more examples. Sam might have that expectation of growing old and sitting on the porch together, but I really don't think Dean did. Of spending the rest of his life close to Sam, sure, but not like that.
I'm curious about other people's takes on Ed's line about not wanting to have a jellyfish spine anymore. Was he trying to say he feels like a doormat and wants to stand up for what he wants? I should rewatch that scene before I try to figure out what the show might be trying to say about Dean there (since it was obviously trying to establish comparisons between the brothers and the Ghostfacers).
Also, the part with Harry's ex-girlfriend and normal life seemed very season 8-era. But forgetting that it wasn't Dean who prompted the Sam-Amelia break up(s), and that Sam demanded Dean drop Benny and wasn't happy about Dean leaving for a day to take care of "personal crap" even before he knew about Benny. The Ed-Harry relationship was presented as pretty one-sided clingy, which really isn't how the Dean-Sam relationship is. So I'm not sure how to take that, as either the show's honest perception or as an intended contrast (there were some very clearly intentional distortions to that mirror, like Dean killing one villain and Harry killing the other, like Harry walking away from Ed, but… how much do I really trust the spn writers?). Also, Harry's reasons for wanting to keep working the Thinman case seemed like it could be an unflattering take on Sam's motivations to do the trials.
Finally, and I'm just going to leave it at this for now, but Sam really needs to show some more introspection for me to not be very, very frustrated at his 'secrets ruin relationships' and 'some things you can't forgive' lines. Or at least the show needs to have that introspection.
