A lot of people think that Shakespeare's plays were about life in general; they deal with such familiar matters as friendship, love, marriage, parenthood, jealousy, ambition, anger, revenge, and the class system, which we all have to deal with. Personally, I have learnt a great deal about what it is to be human from Shakespeare's plays. The fact that most of Shakespeare's characters were fictional is irrelevant: the reality of Hamlet's indecision, King Lear's madness, Othello's jealousy and Coriolanus's pride doesn't depend on the historicity of their characters.
In fact, the total of Shakespeare's combined works was about 38 plays (including The Two Noble Kinsmen, but excluding the lost works Cardenio and Love's Labour's Won), the 154 sonnets, the narrative poems Venus and Adonis and The Rape of Lucrece, and other poems such as A Lover's Complaint, The Passionate Pilgrim, and The Phoenix and the Turtle.
What do you mean when you say 'it is thought that the total # of Shakespeare's combined works ... were between 2-4B'?
As you say, a great many books have been written about Jesus, and the authors of these books differ widely in their interpretation of the man and his teaching. (So far as I can judge, these interpretations range from the historically plausible to the utterly fantastic.) Exactly the same is true of Shakespeare's works; there have been many books and articles written about them, with a very wide range of interpretations. The sheer range of interpretations casts doubts on all of them and suggests to me that we should be cautious in adopting a particular interpretation of Jesus (or of Shakespeare's works, for that matter).
What seems to me to be the fatal flaw in Christianity is that Jesus, and all the New Testament authors, taught that the end of the world was coming, that Jesus would return to judge the world in the lifetime of his hearers (Matthew 16:28, Matthew 24:34, Mark 9:1, Mark 13:30, Luke 9:27, Luke 21:32, Revelation 22:20), and that after his return everything would be different. However, at least 1980 years have passed since Jesus's death and he has not returned. More seriously, since Jesus did not give instructions to his followers about what system of government they should have, or what type of church organisation there should be, European societies for more than a thousand years after his death were modelled on the Roman system, for want of anything better, and the expectation of a supernatural intervention discouraged any human attempts to develop a better society.
I know that this is a long way from the topic of the possibility of knowing the Earth's age, but it seemed to me that your post demanded a long and careful reply.