I've had very little exposure to formal considerations of punctuation (middle school, you were so lame), so I think you're right on my instinctive elocutionary bent. I'm not entirely clear on how much that diverges from the syntactic school of thought, though. Can you give some examples of where a sentence or paragraph might be syntactically correct but not intuitively elocutionary? If that makes any sense.

An interesting consideration might be to look for parallels between exposure to people reading aloud and elocutionary/syntactic perspectives. I wonder if kids who are read aloud to expect books to have a "sound"?