It sounds like you are saying that you got it worked out. As you noted you can delete a server behavior on the page through the server behaviors panel without any confirmation. Also, you can cause a server behavior to no longer show in the panel if you modify any part of the code for it on the page. The server behavior will be recognized with the default code it creates, but not with modified code. It is always a good idea to make a backup of any working page before making any changes in case you need to go back.