There is also, of course, Emily's resistance to accept the death of her father. She meets the townspeople showing no signs of grief, and insists that her father has not actually died. It takes three days for the town leaders to convince her to relinquish the body for proper burial.
This scene foreshadows Emily's most resistant moment. When Homer Barron appears to be on the verge of leaving her, Emily prevents this through murder, keeping his body always with her. The townspeople find the skeleton in her own bed, having been there since she permanently prevented his departure.
Even though Emily has no money and lives in poverty until her death, she refuses to give up Tobe, her black manservant. This would be a part of life in the "Old South" that Emily would not have considered giving up since she still saw herself as a lady.
When the city's leaders come to collect her taxes, Emily refers them to Colonel Sartoris, thinking that he's still alive. This shows how delusional Emily has become, not willing to let go of the past. She resents the men from the "New South" because they don't give her the proper respect she feels she deserves, the kind of respect shown her by Colonel Sartoris.
Emily doesn't allow the town to attach a mail box to her door or put numbers indicating her address on her door. That wasn't needed when Emily was younger, and this also indicates that she has become lost in the past of the "Old South".
For about six or seven years, Emily teaches china painting to the children of the town, thinking this activity would still be of interest to girls of the town.
I think that the murder itself is proof that Miss Emily lives in the past. Things change, people die, people move on- but Emily's fear of this natural progression is manifested in Homer's murder. As long as he stays, things haven't changed much for her- she has managed to stop progress 'dead in its tracks'- pun intended. I think another element to her pre-modernistic behavior stems from her perspective of gender... ever notice that the key characters in her life are all men? Tobe, the manservant, her father, and Homer Barron. In a pre-modernistic world, women are dominated by men. It seems to me that she needed all these men to stay around to take care of her, to confirm her status as a true and original southern belle. Which may have been why Tobe just leaves at the end of the story and we never hear from her again. He doesn't seem much attached to her or her traditional ideals.