I'd be looking to get the wheel speed issue resolved first, that will sort out the car revving up by itself. Usually the sensor that does it.
The steering angle sensor can be reinitialised as well, if it's still storing fault codes after that it will need replacing.
There are a number of tests that can be run with the SMG to check pressures and sensor readings, it should be possible from there to determine what the issue is.
Have you had the SMG relay replaced? These really should be on the service schedule
If it's not been used for a while, an Italian tune up wouldn't hurt
