I appreciate your enthusiasm and expertise on this fascinating topic though I must say I see a number of gaps in your assertions.
Remember, you are claiming to represent your understanding of direct written thoughts of God as transcribed from the Prophet. So it is disingenuous to take offense at asking you to see the world through God's eyes. Of course, we all know this is an impossible task but as you say we are given the gift of higher thinking that lets us try as a way of understanding our own limitations. So you missed the Cosmic Perspective or decided to ignore it such as the existence of many galaxies, stars and planets, i.e. God's Creation. You have not been able to show that all of these innumerable other places and world's are dead and free of religion, spirituality or the same thinking ability humans have, indeed if not far superior. Surely, none of those would have the same Semitic languages created by nomads over centuries, including Hebrew and Aramaic in the same family.
Unfortunately, this becomes the problem—a tautology that says the Quran is perfect but imperfect people fail to recognize it. Since many such non-Muslims will also claim the same sort of thing such as Hindus, Christians and Jews for example whereby everyone else is using free will to choose not to follow their correct religion which also have many miracles, poems, artworks, architecture and numerical wonders to back them up (e.g. Kabala, Christian mysticism, Masonic order). No one can doubt the beauty of Islamic crafts but one can say the same for elaborate Hindu temples or in modern times the majesty and perfection of the James Webb Space Telescope, one of the crowning achievements of humanity.
I personally think that such vehement advocacy for a single account, no matter how well preserved runs to danger of putting all your eggs in one spiritual basket. After all, you've only been told about the chain of custody of the Quran but you were not at the place of origin and believe me over 14+ centuries of nomads and kings, there can be no infallible traceable record as scholars will verify.
From Wikipedia: According to Islamic tradition, following Muhammad's death, the Quran was collected and compiled into a comprehensive book. A hadith in Sahih al-Bukhari states that the caliph Abu Bakr commanded Zayd ibn Thabit to compile the written Quran, relying upon both textual fragments and the memories of those who had memorized it. However, some Shia Muslims believe that Ali ibn Abi Talib was the first to compile the Quran into one written text, a task completed shortly after the death of Muhammad. As the Islamic Empire began to grow, and differing recitations were heard, the rasm – or consonantal skeleton of the Quran – was compiled for uniformity in recitation under the direction of the third caliph, Uthman ibn Affan (r. 644–656 CE). For this reason, the Quran as it exists today is also known as the Uthmanic codex.
As you can see in this account there are enormous opportunities for loss, interpretation, misremembering, rewriting and reordering by powerful individuals you will never know. This fully supports my thesis that the ACTUAL word of God was not written down BY GOD but transferred BY MEN to modernity in a series of handoffs between storytellers, scribes and scholars.
Nevertheless, there will always be believers willing to slay non-believers because of wicked human nature and so far no writing has been able to prevent this nor enlighten the masses except within peaceful pockets of cultural uniformity. It is important to remain humble and appreciate others such as the Aboriginals of Australia who have the oldest contiguous culture running on 40,000 years.
I admire your civility, humanity and love of Islam. Peace be with you.