If Whitman's verse is irregular, why does he use inversions like "the scene revisiting" (p. 193) and "some drown'd secret hissing" (p.197)?

Why is the boy's soul uncertain whether the singer is demon or bird (p. 197)?

Why is the word "death" "delicious" to the poet (p. 198)?

Why does Whitman speak of the "scenery" as "unconscious" (p.4, l.111)?

What is the difference between "the knowledge of death" (p.4, l.121) and "the thought of death" (p.4, l.122)?

What is the meaning of the words "tallied" (p.5, l.135) and "tally" (p.5, l.165)?