I just purchase a Holden Commodore 2000, sedan.

I'm not too sure with the indicator stalk, never had that problem, you'll probably find a little pin has snapped behind the steering column However with the mirror, the relay behind the switch could have the wire disconnected for the right mirror, pull your door card off and check the wires. Also check your fuse to see if its blown, but if the left one works i doubt it. The way to tell is if your cruise control will turn on, as they run off the same fuse. Mine used to blow that fuse every month, it had a voltage break somewhere

behind the steering wheel is ring i think with connections for horn and airbags which has to lugs on it to turn the blinkers off, ring maybe broken or the lug has worn down. if it has a sport steering wheel somtimes people forget to remove this part from the original wheel and put it on the new steering wheel.