KODI is running on a Asrock J3455-M board with SSD and BlueRay-drive. The HDMI port goes to a Yamaha Yamaha RX-V685 and from there to a Sony TV-Screen. I'm using a CEC Adapter from PulseEight and the Flirc Dongle (I was never able to wake up the PC via CEC). There is also a Logitech RF dongle attached (however the Keyboard is switched off).
I doubt that CEC, Keyboard or any other USB device is waking up the PC because the wakeup also occurs if nothing is connected to the USB ports.