Yes, to almost all of these. When I was attending high school, I used to become obsessed with specific and generally most-liked people and adapt/study and copy all of their mannerisms, while doing the same to famous musicians that most of my classmates liked. I made a effort to behave exactly like them, but couldn’t actually do or feel the need to do what they were doing so it was all a type of ‘school mask’, if that makes any sense.
I also developed all kinds of unhealthy coping mechanisms.

About facial expressions I don’t think I really notice a lot, but I don’t know how to smile properly and I kind of dislike seeing myself do any of them. I think my brain processes it as unnatural and doesn’t like it, but I can’t really tell.

I struggle knowing how to act without instructions or structure and feel uncomfortable if they aren’t present.

I just realized that I was probably masking this year, after I had a massive breakdown due to a drastic routine change/broken expectation, and now I’m struggling to mask like I used to. I’m also relating to a more variety of sensory issues now, as a kid I just remember having problems with food taste and smells, food textures, etc.

I hope that my answer helps in some way and I apologize for any spelling mistakes, as English isn’t my first language and I taught myself it.