Gradus and the poem

"We shall accompany Gradus in constant thought, as he makes his way from distant dim Zembla to green Appalachia, through the entire length of the poem, following the road of its rhythm, riding past in a rhyme, skidding around the corner of a run-on, breathing with the caesura, swinging down to the foot of the page from line to line as from branch to branch, hiding between two words, reappearing on the horizon of a new canto, steadily marching nearer in iambic motion, crossing streets, moving up with his valise on the escalator of the pentameter, stepping off, boarding a new train of thought, entering the hall of a hotel, putting out the bedlight, while Shade blots out a word, and falling asleep as the poet lays down his pen for the night" (78)

It was said on Tuesday (I think by Morgan) that Shade might not exist--that he simply isn't. This passage leads me to believe that Gradus doesn't exist. He is seen as the personification of the poem, almost as if he is inside the poem, running through the pages and hanging out in the different stanzas. It could possibly be that Gradus is just a deeper layer of the poem. Perhaps the commentator won't meet him until he gets to the ninth rung of the ladder. Shade coincidentally finished the poem on the very day that he died, but maybe it isn't a coincidence at all. Maybe, in the act of finishing the poem, Shade felt that his life was finished as well--that his life was the poem. By finishing the poem, Gradus, this deepest layer, sprang from the poem in some mystical, sci-fi/fantasy way, shot Shade, and jumped back into the pages. Or, maybe after having completed the poem Shade decided that his life was over and that he should shoot himself and push the blame onto Gradus, that deepest layer of his poem.