How often it requires servicing depends on the way you drive your car. For a Race Car, we advise that the LSD is inspected after every season.
We also recommend changing fluids every 2~3 events.

For a street car with the occasional track day, a transmission oil change everytime you change your engine oil is recommended.

As for specialty oils, its not really necessary - there's a thread on that in my posts, you can read up on that.

Hope that helps.