Does an understanding of how the Bible was written, play a strong role in any Christian sect? There is sometimes a misunderstanding or differing opinion of who wrote what in the Bible.  Is this issue relevant to any particular Christian sect?  Does the topic play an important role?
As a Catholic, you study the books of the bible taking into account to whom the books were written. 

The Catholic faith is based on Scripture and Tradition (with a capital 'T'). We realize that in the early church, many things were passed down by word of mouth. In other words from the Catechism of the Catholic Church:


  82      As a result the Church, to whom the transmission and interpretation of Revelation is entrusted, “does not derive her certainty about all revealed truths from the holy Scriptures alone. Both Scripture and Tradition must be accepted and honored with equal sentiments of devotion and reverence.”44


As far as I can tell, there is not great importance placed on who specifically wrote a book, but the author is taken into account while reading the scripture.