1. first the ADDED_TO_STAGE event, 2. then in this event - register the PLUGINEVENT_REGISTER listener, 3. and then after this event has happend - you have the name/object and full access 4. (and don't forget to clean up everything in the REMOVED_FROM_STAGE event)
have a look at the examples sources of the plugins (*.as files in "plugins-sources/flex-sdk-mxmlc/")
all plugins work in the same way:
ADDED_TO_STAGE => PLUGINEVENT_REGISTER => using it -> REMOVED_FROM_STAGE