We don't currently have the full installers available for download from our website, we tend to have people get their installer when they purchase ArtRage 2 from our Kagi store. On our site we will continue to do a patch file for Windows that will update any version to the latest, so a single download should always have you up to date. The system we have been using for Macintosh patches has not so far allowed us to do a single unified patch ( we're looking into this however ), but there will always be a patch to patch anyone's version to the latest from our site.
Thank you for the feedback regarding keyboard shortcuts. If you grab the latest patch from our site to 2.11 that will fix the alt+space shortcut and prevent the colour selection from occuring. The left alt will always hit the system menu for the Window when using Windows, however, you should still be able to rotate the canvas and clicking anywhere in the app will dismiss it.
Hope that clarifies things some!