Mediafire isn't a problem for me but I had to install the last beta version of construct 2 plus 3 plugins that I had to find and install to open your project.
To solve your problem, change the X origin of your Player for the moving animation to 50 instead of 55. (for the 4 frames)
(Put the X behind the X center of your Player: if you put X=1 as your Player origin when the original sprite face right, your Player will be superman)
One thing, you should set the same canvas size for all the Player moving frames, it will be easier for the origin. And you should improve the collision mask for the Player moving frames, this has an effect on the pushing.
If you want to keep an origin at the center of your Player for any reasons, you will have to use another point to apply the force.
[quote:1vttadjp]Point of application
You can also supply an image point when applying a force. This allows you to apply the force from a different position on the object. By default, it's applied from the object's origin, normally in the middle of the object.
If you don't understand let me know.