The race swap I can't defend. They did say that the actress in that Quantum Break easter egg was just someone who they had at the studio for something else that day, so they just recorded it like that, but who knows. My best guess is that they raceswapped her because they already cast David Harewood as Mr Door, and chose to imply that she's his daughter by making them the only two important black characters, and they couldn't make her mother black without having to rewrite and redo too much of the lore.
As for the minor characters that don't even have names or subtitles, all I remember is the guy who talks to his boat like it was his wife, and the biker chick who has the standard "I'm too old for this shit" spiel. Oh, and the old man who works for Big Sauna, and tries to get you to install one in your home.
There's also the lesbian FBC agent, but it's alright, because her and Alex Casey arguing about their ex-wives was actually funny.
There's the black couple that distrusts you because you're a fed for a grand total of two lines of dialogue before they decide to cooperate.