Origin and Development of the Quran

Please read/respond intelligently and respectfully.

Many claimed that the christian bible is so-called 'corrupted' and changed from its original version, and the manuscript that we have today is a counterfeit. The emergence of many English and non-English translations, with various early manuscripts and extra-biblical Gnostic writings have been the point of criticism by skeptics.

But how about the Quran which is claimed to be divinely revealed? Is it uncorrupted, unchanged from its original copy from Muhammad? What is the history, origin and development of the Quran we have today? A read through some sources (Wikipedia and scholarly debate) gives me 4 major points of the Quranic development.

a) The written record by Muhammad and his companions
b) Abu Bakar's decision to compile a single copy of the Quran
c) Standardization of the Quran by Uthman Ibn Affan
d) List of archeological scripts manuscripts today, and the 150 years gap. Which is the official “original” script and what happened in between?