You're right, a ton of games have a brightness option. I'm not sure if the only thing that changed in the camera is the sensitivity but having a slider for that would be nice for sure.
I just checked Unity's documentation and swapping shaders is possible so a toggle should be easy to implement.
I can understand the devs are aiming at one style (and probably don't want to maintain a game that has 2 styles at the same time, at least I personally wouldn't) but that'd be a nice temporary solution until everything is properly addressed and fine-tuned.
Hitboxes probably only need a bit more of tuning so for now it's fine in my opinion.
The masturbation was probably done having controllers in mind and it just translated poorly into the keyboard, it'd need some experimentation.