Mercy,
Downtown Disney and the Boardwalk are the only places I would drive unless I had PS's at other resorts then I would drive there too.
The bus to/from DtD gets crowded late at night.
The Boardwalk is a good escape after Illuminations. Watch the fireworks from the bridge connecting UK and France then head out the International Gateway to the Boardwalk for your car.
Definately don't drive to MK because you get dropped off at the TTC. Then you have to take the monorail or boat to MK.
AK, EPCOT and MGM are all very close to CSR as is Blizzard Beach. Not worth driving. CSR has great bus service.