I have had to edit your question to only ask one question. Please remember that enotes does not permit you to ask multiple questions. However, thinking about the theme of insanity in this excellent short story, you will want to analyse how the woman comes to identify her own situation with the wallpaper, in the end creating an alter-ego that is trapped behind the "bars" of the wallpaper that she "releases" at the end of the tale. The woman is clearly projecting her own sense of being confined, emotionally, intellectually and otherwise, into the wallpaper, and this can be traced with the growing relationship that the narrator experiences with the wallpaper. Perhaps the most tragic moment of this short story is at the end, when this identification becomes complete, and the narrator sees herself as that woman trapped, and says to her husband:
"I've got out at last," said I, "in spite of you and Jane! And I've pulled off most of the paper, so you can't put me back!"
However, it is tragically ironic that although she declares her freedom stridently, her continued creeping round the edge of the room undercuts her protestations of freedom, making it clear that she has descended into new depths insanity. Whilst she may have "freed" the woman from the second layer of the wallpaper, this "prison" has now become real for her, as she assumes the persona of the trapped room and is left to wander around the edge of it.