Apostate prophet tries literary criticism; Quran is repetitive and non structured?

In answer to the video "Walking Away From Islam"

The harmonious, consistent repetitions of various topics in the Quran are primarly meant to stress some important pillars of belief

25:50"And certainly We have repeated this to them that they may be mindful, but the greater number of men do not consent to aught except denying".

The first objective of that literary feature is thus enhancing man's remembrance of Allah 39:23. It also is a way of explaining itself

17:41"We have explained (things) in various (ways) in this Quran".

According to the Quran therefore, its master exegetist is none but the Book itself, explaining itself 75:19,16:89. The Prophet is its second exegetist and interpreter 3:164,16:44,62:2. The Quran being primarily self-explanatory establishes from the onset 2 conditions for its proper understanding; the importance of considering the context of a verse and the fact that the Book is one integral whole; every verse and sentence has an intimate bearing on other verses and sentences, all of them clarifying and amplifying one another. Consequently, its real meaning can be grasped only if we correlate every one of its statements with what has been stated elsewhere in a different context. A full picture of its ideas can be appreciated by means of cross-references.

Allah warns the prophet, in the context of exposing the followers of previous scriptures for their transgressions, not to withhold anything of what he is commanded to convey, or else it would be as if he did not convey the entirety of the message from beginning to end 

5:67"O Messenger, announce that which has been revealed to you from your Lord, and if you do not, then you have not conveyed His message. And Allah will protect you from the people. Indeed, Allah does not guide the disbelieving people". 

This holistic approach was considered by the earliest Quran scholars, down to the contemporary ones. This means the Quran and its meaning isnt locked to the common man's comprehension, provided it is effectively pondered upon. Al-Tabari for example states that the Quran has 3 kinds of material: that which is only known to God, but irrelevant to hermeneutics, that which only the Prophet could explain, but extremely marginal, and that which any knowledgeable person of Arabic language can explain, practically all of the Quran. Al-Tabari included a chapter even refuting the position of those who claimed that only the Prophet can interpret the Quran.

As a side note, the tafsir section in Bukhari includes many interpretations without isnad, and that are not even those of Muhammad, his Companions, or his Followers.

Some Quranic passages are repeated word for word, in the case of prayers or general pillars of faith but in story telling, the repetitions are rarely if ever the same. This is because in the Quran when it comes to reminding of past narratives and anecdotes, the objective isnt dry storytelling and genealogies as in most of the Bible where one can easily and quickly lose track of names, places and other details. These little details, if omitted wouldn't make humanity miss out on anything in terms of guidance, and in fact confuse the reader and distract his attention to trivial matters. The Quran is not a historical record or dry, impartial document: it is argumentative and impactful to get people to believe and actively reform themselves and their environment. Its powerful statements are in an intellectual, spiritual and emotional language that every culture across time and space can appreciate.

The Quran's objective isnt story telling, but "message telling" and maximizing its audience's attention to the precept(s) of the story. Muslims will not be asked on the Day of Judgment the details of the people of the cave or how Noah's flood occurred, how many generations passed between a person and another, the names in a genealogy or whether they memorized the names of people in the Quran. They will be questioned as to how they responded to the lessons from the different incidents and stories related in the Quran. Thus to focus on the message, the Quran injects the passage of a well-known story, whenever the larger context a sura requires it. And when it does so, it only puts the details of that story that are relevant to that specific context.

That is why one sees variations in repetitions, but never contradictions. The only exception to that style of narrative is the story of the prophet Joseph/Yusuf which takes the form of a beginning to end narrative in one place, and a highly eloquent, intricate one at that.

Those unable to appreciate that Quranic style speak of contradictory, or incomplete repetitions. This is because first and foremost they approach the Quranic text with the above Biblical paradigm in mind; the Quran, instead of being read on its own is seen as a garbled version of multiple Judeo-Christian sources. If, however, the text is approached according to its own thematic unities, its lack of historical detail and absence of chronological order become unproblematic. And this is the prevalent approach among western scholarship nowadays. The second common problem for those reading the text occurs when they are unable to connect the different repetitions properly among one another and fail to grasp the manner in which each repetition fits in the context of a particular sura. This a side note isnt circular reasoning as it doesnt presume the notion of textual coherence. It is textual coherence that objectively establishes itself, through consistent repetitions, recurrence of similar themes and notions in different contexts. These repetitions always retain a core meaning, and are always thematically correlated with similar passages in other suras, like conversations and dialogues between the suras.

The brilliant Pakistani scholar Islahi called the recurrence of themes in several suras "complementarity".

A topic which appears at a place reappears in another background and context where the initially hidden meaning becomes quite apparent because the meaning is suited to be developed in that particular context. Teachings, precepts, stories or anecdotes are mentioned in various styles and with different aspects in different contexts and in numerous backgrounds so that if at one place a reader is not fully able to understand something, he can grasp it fully at another place, and if at one place an argument is not fully appreciated, he can comprehend it in the background of a different context. If an element within a story is only meaningful in a specific context, and that in the course of revelation, that specific context does not reappear in a manner so as to necessitate the repetition of that element from within the story, then the element or detail is omitted.

Sometimes an incident is repeated tersely or partly in order to remind the audience and reader of the overall message that is relevant to a particular context, without recalling it of every precise details.

Sometimes a story is repeated by omitting some previously mentioned details in order to reveal some new elements, this way keeping the story brief and to the point, without communicating too much information at once. When it relates the same event at different places it sometimes quotes different dialogues between different protagonists hence the variation in wordings. As also said, this variation is also due to the importance of giving different angles to the same dialogue or incident that is relevant to the context within the sura. Sometimes the characters might also repeat themselves slightly differently from amazement or in the case of messengers quoted with variations it is because during their career they repeated themselves obviously differently at different times.

The Quran, using these literary devices and many others, explains itself

7:58"As such we manage the signs to people who are grateful"  

54:22"And certainly We have made the Quran easy for remembrance, but is there anyone who will mind?".

Another purpose of this style being to strengthen the Prophet in the face of various forms of denial and obstinacy from his opponents at different times. The form of the story would echo a situation similar to that which the Prophet was facing.

Some truths are repeated to emphasize their importance and fix them in the minds of the believers.

Things such as the oneness of God, repeated more than 10 times in certain pages, or the unavoidable day of resurrection etc.

These are things that even if repeated a million times, it still would not be a waste of time or words. The Quran constantly draws attention to those matters both explicitly or allusively because they are realities like the air we breath, which we always need and that require renewal, this way their reiterations becomes a Quranic grace.