1. The speaker in this poem is the persona, because first person is used ("I").
2. The character of the speaker changes from the beginning of the poem to the end. At the beginning the character is unsure in his words and actions, can't find an answer to his questions: "I don't know, I don't know where it came from, from winter or a river. I don't know how or when", "I did not know what to say". The character has also lost his identity: "there I was without a face", "my eyes were blind".
By the end of the poem, the speaker 'finds himself' as part of something, part of the "void", "mystery", "part of the abyss". He finds himself going with the flow, wheeling "with the stars", "my heart broke loose on the wind".
3. a) The kind of images used most often after the line, "and suddenly I saw" in stanza two are connected with the nature and its flow: "palpitating plantations", "shadow perforated".
They are also connected with how the world opens for the speaker: "the heavens unfastened and open".
b) This imagery contributes to our understanding of the speaker's thoughts and feelings when he first encounters poetry, because the reference to nature helps the reader to understand the idea of the poem. Nature is something everybody understands regardless of nation or education.
4. The speaker's first lines of poetry could be "pure nonsense, / pure wisdom". They could be nonsense because he is not guided by his thoughts, but the poetry simply flows in him and he writes it. The lines can be wisdom as well because of the way the poet receives his ideas and puts them into words.