Johann Sebastian Bach is undoubtedly among the most celebrated of Baroque composers, and to many the great composer in all history. The era of the late 17th and early 18th centuries in which he lived, however, means that his life was not as well documented as (say) Beethoven's was.
In particular, I am interested in the following points relating to his musical career and pursuits:
Bach came from a family of notable amateur and professional musicians. Was he exposed greatly to instruments/musical theory/composition at a young age?
What sort of formal training and musical education did Bach undergo?
Was he self-taught in one or more areas of theory/composition/performance?
Bach's style is often said to blend North & South German with Italian (and even French) styles to varying degrees. Did any in particular dominate him? How did he acquaint himself with such a wide range of music at the time?
Which contemporary/past composers did Bach most admire, and which influenced his own music most? (I am aware he transcribed many of Antonio Vivaldi's pieces, and was also familiar with Buxtehude's work.)
How much do we know about these things? Or if little, does anyone perhaps have any educated opinions in these respects?