Greetings in that Divine and Most Precious Name of Our Lord and Savior Jesus Christ!
Of course the Old Testament it allegorical, that is entirely the point of it! If Noah's ark is not an allegory of faith and hope operating through works in the face of adversity or if the Burning Bush was not the Virgin Mary, what were they?
The reality is that ALL life, all experience, all of our occurrences are allegorical, all that was, is and shall be. God operates within that material world, and all of our lives are the testimony of His operations and power. To say they are allegorical is not to diminish the realness, I feel quite the opposite, to find allegoric value in life is to make it all the more real.
The Old Testament events are true to historicity, but accuracy of facts of events, people, places is almost irrelevant to the deeper, spiritual meaning behind the stories. This is precisely why we have passed down these stories for thousands of years, to preserve and transmit their deeper meanings and content.
Literalists who get into legalistic debates about the Scriptures miss the point entirely of the Scriptures, not to prove the ideas of men as being factually accurate, but rather to demonstrate effectively the continuous activity, economy and power of God in the past, up unto the present, and ever through the future. But it is indeed crucial that we retain awareness that the Scriptures are history, as this is the very proof that the deeper spiritual meanings/causes are also real. God is real, and how He operated in the past is a demonstration of His realness, and it is meant to inspire us to grasp for God's presence in our midst, today, in the here and now, as God operates today with us as actively as He did with Abraham, Moses or David.