That's odd, C2 doesn't have any motion blur at all. Motion blur is an expensive and/or difficult shader technique. Are you sure what you're experiencing isn't the pixel response time of your monitor? My previous monitor had a very good pixel response time, and had no blurring at all. Then I got a new one which has much better color and contrast, but a much worse pixel response time, and now objects 'smear' a bit when moving quickly.
Also, are you sure the stuff you're making is at 100% opacity? If clear background is off, and there's only 1 layer at 90% opacity, then you'll get a bit of ghosting (the previous image remaining partially visible).
Do you have screen video capture software? Fraps has a free version if you don't. Could you capture video of both something you made with this problem and something played also on your computer that's fast and doesn't have the problem? Even capturing just a screenshot of the effect would help to determine what it is. If you can't capture the effect, it's most likely your monitor.
As for the screen tearing, I notice I get tearing in Firefox but not chrome. Chrome has a flag that you can set to use vsync or not, but you should check your video card's settings, as I think some computers have override settings on a per-application basis, meaning setting chrome's flag might not fix it because the control panel is set to override it.