What are some unaswered questions or ambiguities in As I Lay Dying?

I'm just looking for anything about As I Lay Dying that people are still debating about. It could be about plot, the use of a literary technique, themes, etc.

Darl's insanity, for example, would not count because Faulker already confirmed that Darl was indeed insane, so there's not much to debate about.

Any thoughts?

Thanks!!