Never used 9patch, sorry. You might send and email to about the 9patch issue with an example capx.
As for game center, it's nothing more than setting the social service to GameCenter in the CJS object properties. Then using the request login event.
How are you trying to test it? You need to be testing on a device in Xcode and that device needs to be set to use sandbox gamecenter account in the gamecenter settings.