questions and sub-questions in phonology

The outline of the hierarchy of these 16 questions. (1.2.3. for my own questions, I, II, III, thus for those in the book, and the VIII is parted, into a,b, and c, as three questions.)

Important questions of phonology

(7) How do we define the border of phonology?

(2) What is the structure of sound system?
(I) How is language and its parts, including words and morphemes, represented in the mind of the speaker; how is this representation accessed and used? How can we account for the variation in the phonetic shape of these elements as a function of context and speaking style?
(V) How can the functions of speech be enhances and amplified, for example, to give permanency to ephemeral speech, to permit communication over great distances, and to permit communication with machines using speech?

(6) What is the formation of speech sound?
(VIII b) Why is the vocal apparatus different as a function of the age and sex of the speaker?
(II) How, physically and physiologically, does speech work—the phonetic mechanisms of speech production and perception, including the structures and units it is built on?

(5) How do we acquire/learn the meaning of sounds?
(VII) How is sound associated with meaning?
(VI) How is speech acquired as a first language and as a subsequent language?
(IV) How can we ameliorate communication disorders?

(3) How language change affects phonology?
(III) How and why does pronunciation change over time, thus giving rise to different dialects and languages, and different forms of the same word or morpheme in different context? How can we account for common patterns in diverse languages, such as segment inventories and phonotactics?
(VIII a&b) How did language and speech arise or evolve in our species? What is the relation, if any, between human speech and non-human communication?

(1) What is the current methodology for phonological research?

(8) What is sign language phonology about?