Hi mikan,
I have a rather different suggestion for you, how to improve your pictures. At least, this is what I am doing exclusively after experimenting, which now I see it was just pure wasting of time. So, leave the camera at the default settings. I think that the camera manufacturers know the best what is the best setting for their products. Instead, apply some post processing to every picture, which you feel could be improved. And you can do this while shooting JPEGs. OOC (out-of-camera) JPEG pictures, if they are not completely damaged by a huge exposure deviation, can be easily mildly post-processed. I am using the ACDSee (PC) application for my picture organizing/processing. But any photo editor will do the same. My post processing consists mainly in the "Lighting" modification. Such a way I can darken the (mildly) overblown skies for example, or to lighten areas in deep shadows. Yes, the cameras like Canon S90 (I believe that your G9X as well) can make such "improvements" directly in camera. It is called the "i-contrast" in the S90 for example. But I am not using it any more, as as was not happy with the results. I prefer to make such corrections myself in the ACDSee application. On the other side my Pentax cameras make a decent work by extending the dynamic range in camera. I have no clue how this works in the G9X, so try it. But even if it works well, you might need to do further tuning of your pictures, so do not be afraid doing so. Again, you do not need to shoot RAW pictures for such mild post processing. I used the RAW shooting and frankly speaking, I was not able to get even equivalent pictures to what my cameras were delivering as JPEGs.
Peter