P0720 Output Speed Sensor Circuit Malfunction
P0600 Serial Communication Link Malfunction

DTC Codes - P0600-P0699 - Computer Output Circuit
This set of codes are associated with the PCM (Power Control Module)

DTC Codes - P0700-P0899 - Transmission
These set of code are associated with the Transmission and its module.

Nothing to do with the EPS/ABS. Since the codes covered 2 different modules and symptoms indicate flashing lights and spoiler deployment, maybe the RCM (relay control module) might need some attention. Just a guess but the link to the RCM module repair is a lot cheeper then ether of the other modules..... Just a guess