1) Yes, this is the latest.
2) You do not need to edit anything. Please set your configurations in the GPIF state machine, and then in the FX3 firmware-(in the main function, you will need to set the IO matrix as per your requirements. You will need to set the I2S, and disable the UART). The GPIF setting is for pin availability/mapping, the actual declaration you have to do in the IO matrix configuration in FX3 firmware.
>> Please check and update if you see any problem. Thanks for bringing this up