Hey, sorry for the delay. I don't login here so often.
You actually disagreed in just one thing I said, but I feel the intesity of your emotion when you say "several" haha. Anyway....
Regarding what you disagreed, which is the MC character's malice, I would say that his actions can be interpreted in more than one way and I think this was made on purpose, so you can see what you want in him. So his personality is kind of open to interpretation up to a point. I'm sorry I don't remember details since I played the game just once and it's been a little while, but as I recall, he immediately turned off his gentleness when in bed with Evie, with Shino and I think with Luna if I'm not mistaken. That may be him adapting to what the girls wanted him to be in bed. Some people like to please, even though he was called "dominant" once.
His surface is super sweet, docile and purposefully naive sometimes (I can't recall details to confirm if the naiveness is up to interpretation), but in the act of sex he wasn't reluctant AT ALL. Once he had the confirmation that they were really up to it, he was onboard straight away. Regarding to the first declines, well, it's really all part of the dance, of the game. He wouldn't be interpreted as a good guy persona anymore if he accepted right away. What people say and what they really mean isn't always in sinc. That's not to say he is cold calculating. Maybe he is also trying to have a connection while also wanting sex, maybe he is just horny as hell and never decline sex (again, the first declines are mandatory, if your game is being nice). In any case, if he is not cold and calcutaling, that would make him an imature teenager that acts according to his impulses has strong emotions, those which he can't control so well. An immature boy playing game with immature woman and some girls on his level of mentality.
Think about it, if they want to actually bond, why don't they care about about sharing him? Is monogamy just natural to us humans or is it just our culture to blame? (anyway, long discussion I'm not willing to get in).
I would say that some of them want to feel heard and have an emotional connection, like Rebecca and Lucy, but others are just horny. Lucy not caring about sharing first and then beying jelous later is an interesting shift in her feelings. But we don't get these kind of insights on the MC. The author didn't make a good job in explaining the MC's motifs, morallity and internal conflicts. He doesn't sound conflicted about fucking everyone.
Regarding his mother's personality, I think it's yet to be developed. I was actually relieved, deep down, that she wasn't developed too much, I wanted (still want to) to belive that he wouldn't try to fuck his mother and vise-versa, I'm not into that. And as to Shino, I think she was developed as much as everyone else, with exception of the the body-guard. But he's supposed to be this way, cause it's funny this way haha. He reminds me of one Rick And Morty character from that episode of post apocaliptic Earth.