"Jumping to 0x0000 does complete the necessary startup_code that keil generates"

Yes, that's what I meant when I said,
"It [jumping to 0x0000] will restart the 'C' runtime"

But my caveat still stands:
"[jumping to 0x0000] will not reset any of the processor logic, registers, etc, or any other hardware which might be reset by a real RESET..."
and Michael has also explained this.

The only way to ensure a full reset, as Michael said, is to ping the processor's RESET pin; eg, by letting the watchdog bite!