After playing this game (loyal path to the point where we meet Amanda's family), I really like Amanda and Lauren. About MC, I'm not sure about how I should feel/act/react and what Dev wants my MC to be. From time to time he acts like a normal person, then switches to rapey* face mode in his inner monologue.
Amanda meets with other girls, and MC acts guilty even if you were on the loyal path. There are too many homewreckers that surround MMC. MC's friend group feels like they are setting up our MC for failure by riling him up and letting him brag to them about his sexcapades.
Regarding the MC's inner monologue, it has already been stated in the changelog that script revisions are an ongoing process. Older dialogues and inner monologues are being grounded, improved, and fixed as development continues. For example, the Chapter 3 intro has been completely changed and most of Chapter 1 has been improved. Initially, the MC was written with a specific edgy mindset, but as the game and plot have progressed, his thoughts and dialogue are being revised to reflect a more nuanced character arc.
As for why the MC acts guilty even on a loyal path, that has already been visited to an extent with some backstory in
Chapter 6 regarding his past relationships, but there is more to it that we may or may not have fully revealed yet. His guilt isn't always about what he has done, but sometimes about what he is tempted to do or the secrets he keeps.
As for the friend group, they are simply written as a 'boys will be boys' type of circle. If you compare the meeting in Chapter 7 with the one in Chapter 4, you will see a clear difference in tone and maturity. They are there to be friends and reflect a certain social environment, not necessarily to force the MC's hand. Their influence is limited to what the MC allows.