It helps to know geography, history, anthropology, metaphysics, rational psychology, art history, architecture, biology, metallurgy, literature, poetry, music...
It helps what??? The bible isn't written to intellectual linguists...One doesn't need to know any of that stuff to know the God of the scriptures...There is nothing in those things you listed that will help you find purgatory in the scriptures...
http://www.catholic.com/tracts/purgatory
http://www.aboutcatholics.com/beliefs/where-is-purgatory-in-the-bible/
http://matt1618.freeyellow.com/purgatory.html