I believe that your code 35 should be a 25 if it is to refer to idle control.
Since both of your problems seem to intermittent, it will be hard to tell exactly what to fix. However, replacing the idle air control valve, located on the throttle body, is indicated by the code 25.
A slightly more complete description of 42 is:
An open or shorted condition detected in the auto shutdown relay circuit. An open condition detected in the ASD relay output circuit. An open or shorted condition detected in the fuel pump relay control circuit. An open circuit between PCM and fuel gauge sending unit. Circuit shorted to voltage between PCM and fuel gauge sending unit. No movement of fuel level sender detected.
The ASD relay provides power to several circuits, and if it were me, I would replace that relay.