Oh, I know exactly what you mean about regretting not bring the regular "good" camera - since my surgery I can't yet pickup my camera - driving me crazy!
For the grainy stuff - see if you can manually set your ISO - set it as low as you can. This will work for all outside and flash shots. If you can change your ISO - the camera should automatically adjust for you.
For inside shots without a flash - you may need to raise the ISO.