Trimming out Flex dependencies. Removing air.logger.FileTarget and protocols.dict.*, along with everything they pulled in, reduced the swc size by 75%.
Removed functionality that depended on mx localized date/time formatting: DateUtil and WSSEUsernameToken
Pulled Base64Decoder/Encoder directly into this project, to remove dependency on Flex resource manager, shaving off another 50% off of the SWC size.