The theme of the poem "Landscape with the Fall of Icarus" by William Carlos Williams is exactly that, the Fall of Icarus. This theme was explored many times throughout many major works, however here it is explored as a background image, not noticed by hardworking people in the sun. Icarus falls and drowns, and nobody bats an eye.
It is necessary because if you don't have a confirmed opinion with textual evidence to back it up you wont have a good argument.
1. I believe its youthful energy and life.
2. Repetition? Not sure.
3. The "fire in my head" symbolizes the intense drive to go fishing.
4. The mood is defiant. He will prove the reader wrong by finding her.
5. It establishes a mournful, weeping tone.