One who denies the supernatural, may as well forget all about Christianity. Note also that inspiration does not suggest that God approves all the Bible's statements. This is one reason why we need to study the Scriptures carefully, and be diligent about rightly dividing the word of truth. Inspiration is verbal. The Holy Spirit accurately guarded the words.
Inspiration is plenary.
All Scripture is inspired, not merely part of it. That includes the Book of Jonah and also the Book of Genesis. That includes the parts you can't understand as well as the parts you can understand. All Scripture is inspired of God. The whole Bible originated with God.