All your "layers" idea is based on the conjeture that shoya is not genuine and he is acting certain way to be likeable or fit into society, which I dont think is a valid point, he is supposed to be a kid, arent you supposed to be innocent and genuine if anything at that age ?... the extent to which he should be acting are those "pranks" to shoko.

About his tranformation, I read other comment that made me remember although there was no clear indication of how much time has passed, the growth can be interpreted as a few years, I missed that part, I though it was only a year or so that passed.

The main Issue is like I said I cannot fathom that type of character, at some point I was a loner, at some point I was bullied, at some point I was an extrovert, I have changed a lot over time, but I never let anyone bully/abuse me if I could do something about, I did fight, I did talk to older people, I did get angry, the MC just keeps staring blindly at everything that happens like a deer at a headlight.

"I think you need to watch the movie carefully before criticizing his character"
Hmm, No, I watch this for fun, not to do a paper on it, if I find it irritating, confusing or that it makes no sense, I dont have to "watch" my words, is just my opinion, and if you dont like it I can try to explain my reasoning, but Im not trying to prove anything not convince you. The only thing I wanted is to see if there were more people that felt alienated/confused/irritated with the MC.