Short answers, pulled from the story.
Nicolaus Copernicus began developing his heliocentric system by 1514, possibly after returning from Italy in 1510. A physician's library list from that year mentions a manuscript matching the description of his early work.
Johannes Petreius printed the book in Nuremberg just before Nicolaus Copernicus died in 1543. Georg Joachim Rheticus arrived in Frauenburg on the 2nd of May 1539 to study under Copernicus and urged him to publish the work.
Andreas Osiander added an unsigned letter titled Ad lectorem de hypothesibus huius operis before Nicolaus Copernicus's own preface dedicated to Pope Paul III. This anonymous foreword claimed the heliocentric system was merely mathematics intended to aid computation rather than literal truth.
The Sacred Congregation placed De revolutionibus orbium coelestium on the Index of Forbidden Books on the 5th of March 1616 more than seventy years after its publication. The decree suspended the book until corrections clarified its status as hypothesis rather than certain truth.
Owen Gingerich found 276 copies of the first edition during his census of surviving volumes. Nearly all leading mathematicians and astronomers owned these volumes but ignored the cosmology at the beginning while focusing on planetary motion models in later chapters.