OSX:

I managed to get Cycles standalone running on OSX, also managed to write out an .xml file into the temp folder with your script!
Then with Terminal, I rendered it with Cycles. With this script:

/Applications/MoI\ v3.app/Contents/Resources/drive_c/moi/cycles/cycles /Applications/MoI\ v3.app/Contents/Resources/drive_c/users/Wineskin/Temp/ball_square_scene.xml

But not a programmer, so didn't understand how to edit your script so it does this automatically.

http://blender.dingto.org/cycles_standalone/Cycles_OSX_10.9_x86_64.zip