Hello Valkain!
I really like your constructive criticism! I totally understand your concerns and/or reasons behind the different points you make.
And you're tackling a FUNDAMENTAL aspect of storytelling: the suspension of disbelief.
~~{It might seem like I'm rejecting many of your ideas at first glance, but please keep in mind that I agree with most of your comments and that I'm bringing my take on your observations in order to add fuel to the debate, the discussion!}~~
Sure, during my first playthrough (I've just started my 2nd playthrough today), there were a couple of details that really shocked me, really making my mind go into a "WTF mode" at first, especially regarding the funny cooking reactions. But to be honest, I find this to be a very creative and humourous approach that just contributes to this Visual Novel's originality and that makes it stand out from the rest. Yes, the first food tasting scene felt a bit weird, but the consequenses were hilarious! But while it hurts a bit the suspension of disbelief, it creates a big mystery... And that's where it doesn't matter if it slightly affects the suspension of disbelief: because it serves the story much more. And as we slowly learn more about the MC's past, we're slowly gaining an understanding of what happened and why... We don't nearly have all the answers yet, but I find that the "ecstatic food tasting experience" is an interesting part of the story and a fun mystery!
~> FIGHT TALK: Having trained for over 12 years in Martial Arts and Combat Sports, I can definitely say that you CAN have a form of conversation while sparring and in certain types of real life (combat) situations, and sometimes... you can't: it really depends on the context.
A long monologue is ridiculous, except for when you're in control of the situation, like when the @$$hole tried to stab his GF and the MC had a strong hold of his wrist, to which he was applying constant force (very painful) up to the point where he crushed it.
And also, I don't think it's appropriate to expect hyper-realistic fighting scenarios from a Visual Novel. The author has been doing an incredible job of keeping the fight scenes as close to a real life scenario as possible!
~> I understand what you mean by saying that the MC is "TOO GOOD AT EVERYTHING AT A VERY YOUNG AGE."
But regarding the Fighting and Cooking Skills, I find that there is absolutely nothing wrong with his skills' level, here's why:
Fighting: As demonstrated early on, he might be good, but he's not OP (Overpowered). From the first scene (his traumatic experience), the MC is shown to be a normal human being, as he says many times later regarding this incident that he's not a manga hero that can take on 6 guys by himself... In fact, he got his ass brutality kicked... And in chapter 5, we again see his limitations...
You said you didn't have any problems with the MC's fighting skills as of chapter 4, and I can tell you that NiiChan isn't going anywhere near superhuman unrealistic fights. I wouldn't have any problems if the characters displayed extreme levels of fighting skills, as long as they didn't go into Marvel, Matrix territory, but as I said: from what I've seen, I'm sure NiiChan doesn't plan to go into crazy manga/anime territory.
~> Still about the "MC's too good at everything for a 24 years old", I REALLY THINK THAT THIS POINT ISN'T ENTIRELY VALID.
FIGHTING & COOKING SKILLS: Anyone who starts training at a very young age for a specific skillset and dedicates his whole life to his training over many years will become exceptionally gifted. And if your parents are masters in their field and that they're the ones who train you, you're going to reach mastery by adulthood...
So I really don't see what's the big issue with being a very good, but not super great fighter, and having developed his mother's supernatural cooking skills to a certain degree...
MONEY-WISE: You've got a point. Coming from a very poor background, it's unlikely that he'd have been able to afford that kind of car. I had NO IDEA how much his car is worth, checked... And HOLY $HIT!
Yeah, it's highly implausible that the MC could have afforded his car, but he's mentioned that he had been working multiple jobs over many years to gather enough money. But seeing as he's been working for years at high paying jobs in Tech Companies, IN A FANTASY SETTING, I don't find this to be such a huge stretch...
I mean... Come on! Yeah, many aspects of the story need to be plausible, but as with Hollywood movies, a big part of the story is about dreaming! And some liberties with social status and lifestyle are very minor details for me, and I suspect they are for the majority of the players...
If the MC could shoot laser beams out of his eyes... THAT would destroy my suspension of disbelief!
~> One last point. You said:
"[...] although I saw it weird how fast he switched from introversion to social in less than a week, considering that at the start of the game he still has issues with his past."
I'm sorry, but I strongly disagree with you on this. Have you ever suffered a traumatic event that caused you a Major Depression? I have. Multiple times.
The MC was 2 years in his depression at the beginning of the story. Even though he was still affected by the past, even though he still though about his trauma from time to time, there were many indications, subtle but very well though of clues in the "intro" (up to the first few days at the house) that, when put together and analyzed, gave a pretty good picture of what frame of mind he was in and at which step he was in his recovery process.
Someone that has been hurting for years inside and has a strong fear of opening himself again, allowing himself to feel emotions again, especially loving again, can SEEM like an INTROVERT. But unless it was the case before the trauma, it doesn't mean anything.
At the very beginning, the MC had already been through a big part of the recovery process. He had reached acceptance, and without going into a lengthy psychological analysis, I'll say that while he still had feelings of guilt and shame over failing to protect and find Irene, those had already been fading away in frequency and severity for a while (the opening dream: he said it had been a while since he had it).
From my personal experience and psychological studies, and from the infos given early in the game when MC moves to the house, it's clear that he was ready, "ripe" for his final step: letting go of the past.
And that's exactly what everyone at the new house told him, showed/taught him by forcing him to live in the moment and experience good feelings, showing him that it was still possible to have positive emotions.
I'll end with saying that the story illustrates one of, if not THE best way (in my experience) to free yourself from this kind of burden.
A total change of scenery, going from living alone to live in a house full of new and supportive people. New job, new town... The more drastic the change, the better!
Meeting new people, especially from the opposite sex, in a positive context/environment, combined with the previous elements, is THE PERFECT SETUP TO TRIGGER A TRANSFORMATIVE EXPERIENCE, a sort of Rebirth.
Meeting, flirting and feeling that people are interested in you for who you are, having $ex, falling in love (even better), can seem silly, but for someone in the MC's Situation, it's like pulling your head out of the water after so long and starting to breathe again, it's really a life changing experience, the electroshock that wakes you up from your stupor, from your old emotional and psychological patterns that were only sustaining a depressive state!
So, I find that the MC getting out of his protective shell (as opposed to being introverted, something he never really was) in the first few days at the new house is just such a brilliant example of how people who are stuck in the past can experience a transformation that enables them to let go of their psychic chains and live again!
I have no idea if NiiChan had thought of this when working on the story and the Main Character's psychological development...
Maybe it's just a coincidence, but all the elements to support such a deep psychological insight are there!
So I would have a hard time believing that it wasn't deliberate on the author's part!
Take care!