On the reactions of the MC's relationships, what I imagine:
Josy and Maya, most of them already seem to know there's something going on between them, and Tommy's the only one who might not approve, but honestly, I think they'll work it out quickly, he won't like it, but he'll accept it.
Sage, again everyone should expect this, the only one who comes close to caring is Quinn because she also likes the MC.
Quinn, in Quinn's case Sage is the only one who seems to support, the others either don't care or won't like it, especially Tommy, Josy, Maya and Derek.
Lily is something very new, something I didn't expect, I still think she's just using him, investing in him, so I'll imagine the other characters will think the same, the MC is becoming popular, he barely became a DIK and already he is making decisions and commanding everything.
(She might start to really like him in the future, but I don't see that at the moment.)
Nicole, I think everyone is going to think he's retarded, an older woman with a kid, come on. (How old is the kid, 15?)
Riona, it's possible there's something more serious in the future, so anticipating that, I believe everyone will be happy to know that Riona and the MC are in a serious relationship, everyone seems to like Riona, only Quinn wouldn't like it if Riona said that she would stop the restaurant thing.
(For those who don't accept her past, remember that the MC also had sex with everyone there, he's not that different.)
Jill and Bella, I never had the patience or interest to try anything with them, so I don't know their circle and how they should react.