Concerning your question about "The Yellow Wallpaper," you mention the literary terms, but don't list any. I'll assume you can use any literary terms, then.
Conflict is one term you could center on. The conflict centers on treatment that could actually help the female patient and the sexist, ignorant treatment prescribed by her doctor and husband and the male medical establishment at the time. Males believed that females were intellectually inferior and that overuse of the female mind could lead to mental illness. Thus, the patient in the story is ordered to not write or think, etc. This directly contributes to the escalation of the woman's break from reality. Kept from any intellectual stimulation at all, the woman's intelligent, creative mind seeks any possible outlet for activity.
Conflict, of course, is integral to the plot. It drives the plot and creates suspense.
Point of view is also an essential element of this story. Narrated from the patient's own point of view, the reader is led to believe she is on merely an extended break or vacation. Based on her description and events, however, the reader understands that she is actually in a mental institution receiving treatment. The point of view reveals insights into the patient's state of mind and her delusions. This, in turn, reveals and elaborates the conflict, which drives the plot, etc. You get the idea of how literary elements work together.
The narration is, of course, presented by an unreliable narrator. This is not necessarily a negative, as it may appear. The term doesn't suggest that the narrator is purposely lying or anything like that, although that's possible. The idea is that the story is told from the one speaker's point of view. Everything the reader reads is from only the one point of view. Thus, the narrator is deceived into thinking (or deluded) that she is just taking a break in the country, when she is actually a patient/prisoner in a hospital. She presents her hallucinations, as well, which of course are not actual, though they are certainly real to her. This is accomplished through the unreliable narrator.
Finally, you could also work in characterization. What methods are used to characterize the narrator? Look at character thoughts, character dialogue, action, and description. You'll find that characterization also contributes to conflict, plot, and point of view to present the theme of medical treatment in the 19th century.