This project began as a study of jokes, but that soon led me to studying religious implications of Superman. This blog seems to be an obvious one to study from that perspective (see also entries for Feb. 25, . The writer calls Superman "an archetype of radical giving and effort for a greater good." That seems accurate enough, to a point. If we take archetype as he is using it, Superman is also the archetype of individual achievement and greatness at something, such as sports, sometimes in service to a team.
On an unrelated note, here's an article imagining what it would be like to be Superman's kid. There's been a lot of this sort of thing--working out the real-world possibilities of Superman's existence. Perhaps most famously, Larry Niven wrote "Man of Steel, Woman of Kleenex", which was all about the problems of Superman and Lois Lane's physical relationship.