Ive also spotted this. I have found this little aspect - getting on a ladder makes everything ok until u get of it.

You can always change brightness in your monitor settings, so its a bit pointless

Yeah, making a possibility to attach it with scotch tape is a good and realistic idea.
Ive used flashlight at night yesterday a hour or two, it seemed ok, but it gives a bit small ray while being close to an object.

I support this.

there is a forehead flashlight in game

Yes, had this bug in the same type building north of Kamenka. It looked like i could open the door, but when i tried nothing happened, only indicator changed from "closed" to "opened"

Also those new 10-14 floors high building near cherno, stairs