Apostate prophet wonders; Quran is easy to understand and explains everything?

In answer to the video "The Mysterious Letters in the Quran"

When the Quran describes itself with mubin, it always is in the context of declaring that it is clearly a book from God, not man made. The root is B-Y-N and it means between. The action of the verb is "betweening". This betweening can mean clarifying because one can know better the difference between two things. It also can mean distancing because the betweening makes things become apart. The Quran clearly seperates what is human and what is divine, and it is in that sense that it is mubin, not in the sense of "easy to understand". 

To wholly grasp the Quran certainly is not an easy task and one must beware of a hasty approach to it, drawing wrong conclusions from isolated verses or sentences taken out of their context. One must take the time, allow the whole of the Quran to be revealed to one's mind before attempting to interpret its message

75:16,20:114"and do not make haste with the Quran before its revelation is made complete to you and say: my Lord, increase me in knowledge".

This is how the Quran is 54:17"facilitated/yassarna for remembrence". The "taysir" of the Quran doesnt refer to it being made easy but rather facilitated, ie the means to grasp are within reach but require personal effort.

When the Quran says that it contains the explanation of everything 6:38,16:89 like the previous revelations 6:154,7:145, it means it answers all questions pertaining to salvation, as can be seen from the direct context let alone by having a basic grasp of the book's explicitly stated purpose. These important issues have been made easy to grasp and devoid of any possible room for ambiguity. These crucial matters are expressed in the form of concise and straightforward statements

19:97,44:58,11:1"a Book, whose verses are made decisive/uhkimat, then are they made plain, from the Wise, All-aware"

3:7"He it is Who has revealed the Book to you; some of its verses are decisive, they are the basis/mother of the Book".

UMM al Kitab literally translates to MOTHER of the book. In the highly conceptual language of the Arabs, because the mother takes her child to his goal of physical development, the word came to be used in other contexts for that which help in attaining a goal. In this case, the decisive verses help us reaching to the truth. These decisive verses are well obvious and scattered throughout the Quran. Each of these verses on its own, is Umm al Kitab, just as a group of them is Umm al Kitab. 

Islamic tenets arent the result of centuries of conjectures and proof texting from ambiguous verses, as is the case with Trinitarianism. The Quran states about itself that it is a book dedicated to spiritual guidance so containing "all things" means all that pertains to spiritual betterment just as one reading from the HB saying

Ps119"all your precepts concerning all things"

doesnt need to be spoon fed that the statement encompasses all religious matters relevant to the addressees, not medicine or cooking recipes.

The Quran was revealed to instruct humanity in such a way that no excuse will be left when we will be brought back to our Creator. It is a book of belief, reflection, and invocation, as well as a book of law, wisdom, and guidance. With Muhammad as His last messenger, Allah has finally sealed the line of prophethood and firmly established His religion in its ultimate form. It follows that the Quran must accompany man until the Day of Judgment providing him with guidance. 

This honored Quran 56:77 is a Book of clear light 64:8 with the certain Truth 69:51, sent down from the Light of the Heavens and the Earth 24:35 the Lord of the Worlds 32:2, the Supreme King and Ultimate Truth (al haqq) 20:114,26:192. A favor from Him free from imperfection, incredibility, conjecture, free from any misleading discrepencies, rightly directing to what is most upright and making all things manifest 12:1,17:9,18:1-2. It is wrapped up in wisdom 2:231,31:2, a source of mercy guiding to what is most upright 17:9, bringing the people out of spiritual darkness into light 57:9, to the way of the Mighty, the Praised One in the heavens and Earth 14:1-2, as were the purpose of previous revelations. It is full of the most excellent and just admonition 4:58,38:1, abounding with good, blessings, guidance and healing for the hearts 6:92,38:29,41:44 a verification of what is before it and a distinct explanation of all things necessary for salvation 12:111. It is sent with the truth for the sake of mankind 39:41,10:57,14:52,25:1 not belonging to any particular group of people 24:35, and a proof from the Almighty 4:174 removing all doubts from the seekers of truth and providing evidence against those who choose to disbelieve in it 23:65-67,36:70,45:20. The supernatural importance of this Book is such that mountains would crumble, the earth would rent asunder from its weight 59:21,13:31. This kind of imagery is meant at contrasting those whose hearts are more inert and harder to penetrate by divine guidance, than a massive mountain would be.

It clarifies all the things necessary for the salvation of mankind 16:89 which is why it addresses all the people of the earth 38:87-88,49:13,7:52,14:52 calling for brotherhood in faith regardless of one's race 49:10, sent with a messenger of glad tidings and warnings to all 17:105,21:107.  

It is the Dhikr or the Reminder, bringing back humanity to its original God-consciousness 16:44 and making clear to them on those who were given the Book before that about which they differ 16:64, the Muhaymin (guardian) over what came before it from Allah 

5:48"To thee We sent the Scripture in truth, confirming what came before it, and guarding it in safety" 

It is Al-Furqan (The Criterion), the standard which distinguishes truth from falsehood. The word furqan literally means "that which distinguishes one thing from another" in the context of human God-consciousness 

2:185"The month of Ramadan in which was revealed the Quran, a guidance for mankind, and clear proofs of the guidance, and the Criterion" 8:41"on the day of distinction (yaom al furqan)" 8:29"He will grant you a distinction(furqaanan)" 

as well as in the context of divine scriptures providing certainty in the distinction of good and evil. It is used for past revelations 2:53,21:48 and for the Quran and nothing can overrule this supreme criterion, not the hadiths and not even the Prophet 

10:15"It does not beseem me that I should change it of myself; I follow naught but what is revealed to me". 

It is Al-Mizan (the balance) and contains Divine Justice to seperate good from evil 

42:17"Allah it is Who revealed the Book with truth, and the balance".

 Al-Mizan and Al-Furqan are equivalent in meaning, they both decide between the people with equity, and contain the true knowledge and explain the duties of the servants towards their Lord. These appellations stress the fact that revelation - and revelation alone - provide an absolute criterion of all moral valuation.