For any given object you can get a list of all active event listeners:
http://stackoverflow.com/questions/2518421/jquery-find-events-handlers-registered-with-an-object
Also, CDT an easily show you those as you navigate the DOM.
But regardless the approach, this will inform you as to what listeners are where. But figuring out why or what they are for is a completely different problem. As the author of the app, you should probably have a pretty good sense of what is waiting on what. Though, if you use a lot of third party components, then having a full understanding of every event handler is elusive.
