I know a way to get android l softkeys without rooting though its only for sony devices. Contact me at apoorvsingh574@gmail.com or follow on g+ to know it..
I'M DAMN SERIOUS and it's a DAMN easy way all you got to do is download an android app(whose link I'll provide you) and get these PlayStation styled softkeys without rooting.... I could give a proof but xda doesn't allow new users to post a link