I know you've already called several times, but I think the best thing to do would be call back and check to see if any fare rules on your ticket prohibit changing to a direct flight, either standby or CFC. The AAgent should also be able to give you an idea of loads. In fact, if a flight is available for CFC, it's a good sign that you would clear standby for that flight (unless there's a flight cancellation or other IRROPS).