If the “address is already in use”, then there’s already an instance of networktablet running. Try to log out, log in again and then run “./networktablet” in the console only once.
Edit: I have made a new version of the networktablet driver (please re-compile) that gives better status info.
I’m happy that you like the app. GfxTablet pressure sensitivity is handled by the MotionEvent API automatically. I think if there’s no hardware support for pressure, the API tries to emulate it – so the pressure info should be available to all apps, no only GfxTablet.