To change the animation, I would suggest modifying the RadDocking theme and changing the animations there. The AnimationSelector takes care of the auto-hide animations. LeftIn, Leftout, TopIn, TopOut, RightIn, RightOut, BottomIn, BottomOut
are the animations responsible for the AutoHideAreas.
You can always switch off the animations you just need to set the AnimationManager.AnimationSelector attached property of the Docking control to Null.
I hope this will help with any customizations you wish to make.