p3 俺は無理w Man: "I could/would never [date her] lol." でも美人だよ Woman: "But she's so pretty." 身長差スゴ Man: "The height difference is insane." The bystander is saying that despite her beauty, he could/would never date her because he would feel insecure about her height.
p4 170... ご... "One-seventy... five..." She's embarrassed, mumbling (ごにょごにょ), and reluctant to say the last digit.
p5 なっちゃん、ウチに来た時どうするんだっけ? This is closer to "What are you supposed to do" or "Do you remember what to do when you come over?" Like in a teasing/dominant tone.
p8 付き合い始めた頃はウブだったけど 僕の性癖を知るとより喜んで何でもする様になった。 "SHE was naive/innocent when we first started dating, but once she found out about my fetish, she happily did/went along with whatever I wanted." より here is a comparison in time ("once/since she found out"), not a comparison in happiness.
The rest is just boilerplate porn shit, but stylistically the man should sound more a little more dominant. For example on p14, ちゃんと言ってね probably should not become "please tell me."