Walder Frey points out that all the great houses have always looked down on his house and thought they were better than him, even when they do the same as he does: "People snigger when I marry a young girl, but who said a word when Jon Arryn married the little Tully bitch?"
Balon saying that Theon is no longer his son because he's been emasculated. It does make Theon dynastically useless. Even if Theon survives and succeeds his father, the seat of House Greyjoy will go to Yara after him anyway. Also, given how little respect the Ironborn give Theon before he's castrated, can you imagine any of them following him after? There'd be a rebellion in a week.
Walder also calls Robb out after he claims to not want to rub his marriage in Walder's face, despite his wife standing right next to him at the time. (This is also a Mythology Gag: in the books, Robb left her at Riverrun, both for that reason and because Catelyn reminded him that he would be unable to stand there while Frey insulted Mrs. Robb to her face. Cat may have screwed up some other things, but she hit this one on the head in both continuities!)
Unfortunate Implications: The final scene with the very VERY white Dany crowdsurfing to the adulation of a group of very brown slaves has been called problematic, with Wired's Laura Hudson memorably calling it "George W. Bush's secret fantasy of how he though the invasion of Iraq would go for him. note It should be noted that the equivalent scene from the books featured slaves from all ethnicities; one reason they don't appear here is because the extras were cast in Morocco. Given how thoroughly Dany's attempt to single-handedly dismantle and overhaul the social structure and labor economy of an entire continent is deconstructed in the books, it's entirely possible the vibes were intentional, to make it all the more jarring when it happens in the show.
"So the people that Dany frees in the slaver cities are of many different ethnicities, and thatís been fairly explicit in the books. But of course when David [Benioff] and Dan [Weiss] and his crew are filming that scene [of Daenerys being carried by freed slaves], they are filming it in Morocco, and they put out a call for 800 extras. Thatís a lot of extras. They hired the people who turned up."