Nah that hottie ceo is not dumb at all. That's just her personality. And of course she just pissed at our MC because she is a close friend of Rui Xi, she knows about their past, but she doesn't know yet that they are back together, hence the snarky remarks everytime they meet.
And the kid has no bad intentions. I don't really know what he meant when he said "set him up" (probably they just used the wrong words..), he just wants his family together.