This is one of the "big" episodes re: Shen Wei and Zhao Yunlan's relationship from the time they're still circling around each other! (Another one is Zhou Weiwei the mirror girl, where the boyfriend expressly rejects the Haixing version.) It's very well done, how they put in foils and foreshadowing right from the start.

As for re-examining his attitude towards on Dixingren, I don't think we ever get any indication, even in the earliest episodes, that he dislikes them like his dad did.
At one point in the past, he boasted to Da Qing about killing each and every single one of them. This was likely mostly empty words, but the background sentiment must've been there. He never loathed Dixingren like his dad did, that I can 100% buy, but I think this was still a point where he did some self-reflection and soul-searching and made a note to confront his attitudes about Dixingren some more. I do agree that Shen Wei's "Dixingren are just like regular people!" pleas are hangovers from conversations with Zhao Xinci (or, hell, even from conversations with Professors Zhou and Ouyang!), but I think we see Zhao Yunlan's attitudes drift over the course of the show.

He's really trying to get under Shen Wei's skin, and isn't it amazing how Shen Wei doesn't even stop him? What normal person just lets some cop steal their cake? Isn't his lack of resistance suspicious?
Indeed! Shen Wei is already on Zhao Yunlan's radar, and here he is, being very suspicious. Does he not want the cake his students bought him???

And what normal person goes to the hospital for a cold?
Apparently it is a Thing in China to go to the hospital for the smallest of things!