Writing and Compilation

Q: What is the significance of the word وَلْيَتَلَطَّفْ  in the Quraan Majeed?

Q: I am teaching children hifz. They want to know how/who/when did the Quraan come in to the sequence that it is in? 

Q: Can person write an ayah of the Quraan while in the state of haiz? 

Q: Who introduced Juz in the Qur'aan? Is this a divine division by Allah? or was it introduced much later? Can it be considered part of the Divine code from Allah in order to understand the Qur'aan?

Q: I know that the Quran has never been changed. Did it happen in the history that someone tried to change/add words to the Quran? I know for sure if someone did it, they would fail miserably and it would be discovered because Allah protects the Quran. Just asking if someone actually attempted to change it.

Q: I am a Muslim. One night a thought strikes my mind that "may be after the scientists have discovered some particular thing then the arabs have added those discoveries in the Quran by replacing the previous ayats.

Please try to understand that I am not saying that the Quran is written by humans, rather my question is that may be they have done some mixing by adding the scientific ayats and saying that it is already written in the Quran.

For example in surah "Al ambiya" it says that the heavens and the earths were joined together and we cleft it asunder". My question is that in Surah al Ambiya may be after the big bang theory was discovered the arabs added this verses in the surah al anbiya about the big bang theory?

My question is that was there such adding if scientific ayats in the Quran by the arabs or the Muslims and I am not saying that the Quran is written by humans but my question is that was there any addition of scientific verses in the Quran by the arabs secretly? 

Q: I am a Muslim and I was reading the Quran and a thought struck my mind that "Maybe after scientists discovered a particular thing, then the Muslims or the Arabs wrote about it in the Quran and said to the world that it is already written in the Quran about 1400 years ago. Take embryology for example, maybe the Arabs were advanced in embryology and discovered things about the embryo and wrote it in the Quran or an=bout astronomy". Please help give a logical answer.

Q: Why Uthman (radhiyallahu anhu) had to rewrite Quran when Abu Bakr (radhiyallahu anhu) had a copy already? 

Q: I have question about the قران in سورة روم. in verse 54 the word is ضعْفٍ. So in the Usmani script it says ضَعْفٍ, but in the IndoPak script it says ضُعْفٍ. Why is the symbol different? Can you please clarify me on this issue.

Q: Was Hazrat Ameer Muawiyah radhiyallahu anhu a scribe of Wahi?