1 pointYou would need to take a look at the documentation for the F5529 to verify that it can be awakened with a GPIO interrupt. In a very deep sleep, IIRC, the list of available interrupt sources gets shorter. So if LPM4.5 supports a GPIO transition as a wakeup source you should be good to go.
1 pointCheck the usual suspects: Does the I²C device run at 3.3V? Otherwise, use a logic-level converter. Are pull-ups installed? Try 10, 4.7 or 2.2 kΩ for the SDA and SCL lines. In case the LaunchPad provides multiple I²C ports, is the correct port selected? Try Wire.setModule(0); // or other port number Wire.begin(); Still nothing? Use a logic analyser to trace the signals on the I²C port. (To be continued...)