Read the following sentences: “There would be nothing left of the subway of which he had grown so fond. He made his way back down the tunnel and out one of the access points. He was off the clock for good.”
When the author writes that Tim was “off the clock for good,” what does he mean?

He means that he was gone for good. In other words, he would never return to the subway

Explanation:

as for symbolic actions, the narrator's tearing down the wallpaper in an attempt to find the "woman" in the wallpaper represents her struggle to retain or regain her sanity.   the wallpaper has been part of her confinement and by her tearing it down, she is freeing herself from that confinement.