Can Shotwell be configured to publish the CR2 file to Google instead of the JPEG? I was extremely disappointed to discover that all the time I spend publishing photos was wasted because it used the JPEG versions!
Unfortunately the files it uploads are named IMG_xxx.CR2.jpg so that when you're viewing file details on Google, it hides the jpg extention and unless you notice the file is too small or download the full version you'll never know what happened.
It wouldn't be quite as bad if the JPEG was a 100% version, but it's not. If I use Lightroom the jpges are about 10 MB compared to Shotwell's 2 MB.
These are the RAW files supported: https://support.google.com/picasa/answer/15625?hl=en