In Faulkner's "A Rose for Emily," I do not believe that Faulkner addresses race with a sense of bigotry. His is the voice (told through the unidentified townsperson) that recognizes "traditional" attitudes in the South—though not overtly focused on racial issues: more than this, we see the vestiges of racism as through a window clouded with age.
Tobe is the only black member of the community the reader is introduced to with any detail—working for Miss Emily. Toby is first referred to as an "old man servant" and the only person Miss Emily has allowed in her home for ages, showing her complete trust in, and dependence on, him—especially in light of the story's conclusion.
We may see "class struggle" when the narrator refers to 1894, when Colonel Sartoris...
"...fathered an edict that no Negro woman should appear on the streets without an apron."
(This is a shadow of the slavery era still present in town.) Oppression of blacks is seen in that they are treated as lower class citizens (aprons limited only to women of color) .
When the men visit Miss Emily to collect taxes, Tobe is referred to three times. He was old then, but nothing derogatory is said about him or their reaction to him: they are admitted by "the [old] Negro" and he shows them out. That Miss Emily is in charge, there is no doubt. When she calls Tobe, he appears and complies.
Years before, when the smell appeared to be coming from the house, the women who came to call were not admitted, by the then "young" Tobe; he showed them the door with the utmost respect. The women believe Emily foolish for allowing Tobe to care for her home.
The men use the "n---" word in the story, but it is not used with arrogance or malice, but more as habit (which does not make it less offensive, just indicates old habits and oblivious sensibilities). Faulkner, I believe, is still just describing life in the South here.
We read of Miss Emily's loss of her father, her relationship with Homer Baron, and the arrival and departure of Miss Emily's "relations." Homer has left, but he is seen being admitted into the house one night by Tobe, never to be seen again. Life in town changes as the years go by. Miss Emily stays in, and an aging Tobe runs errands. Eventually, she becomes a recluse.
Tobe's presence is a constant in the story. He serves Miss Emily until her death. He is her connection to the outside world. He "protects" her from unwelcome visitors, and is very loyal.
...we had long since given up trying to get any information from the Negro. He talked to no one, probably not even to her, for his voice had grown harsh and rusty, as if from disuse.
On the day Emily dies, "the Negro" greets the first of the female callers at the door...
...and then he disappeared. He walked right through the house and out the back and was not seen again.
Of all of the information we learn about Tobe, that which most clearly defines oppression and class struggle is his disappearance. We discover—with the fascination of a true horror story—that Emily has murdered Homer Baron. And while she is beyond the law (being dead), Tobe is not. He knew what had happened, but even in a place of service would probably never have been forgiven by the community for any part he played—even if only with his silence—in the death of a white man. This part of the story is where we see that the old ways of the South have not changed enough to protect Tobe, so he disappears when the murder is discovered.
Social classes are an important part of "A Rose for Emily." The Griersons are an old Mississippi family (with roots in Alabama as well) who the narrator relates are "a little too high for what they really were." He also includes insight from the "younger generation" of Jefferson citizenry, and briefly mentions some of the African-Americans who live there as well. Miss Emily's Tobe is described as a "manservant," an old but socially proper term; the author also uses the "N" word several times when discussing Homer Barron. Little boys would gather to hear him "cuss the niggers" on his work crew and hear "the niggers singing in time to the rise and fall of picks."
Faulkner's use of the "N" word doesn't necessarily brand him as a bigot. It is the narrator's words he uses here, and the narrator--an unidentified person who seems to speak for the town--is probably a white man in 1920s Mississippi, where such a description would have been common. Indeed, Faulkner was quite the opposite. He became very unpopular in Oxford, Mississippi (where he taught at Ole Miss) when he spoke out against racisim and segregation.