I agree that barefoot running can be good, but really warn against it if your legs/feet aren't equipped to handle it. Once everything is 100% healed and has been for a while, it is worth a shot to introduce it in, and as already suggested, slowly. Still, if your strength and flexibility around the ankle joint and within your foot is not sufficient, or you have any "biomechanical flaws" (for lack of better phrase), they may be exacerbated by this... just ease into it.
I like the idea of doing it on grass, since the surface may stimulate the touch receptors on the bottom of the feet, and therefore help your nervous system control your foot movement better (and reduce the risk of harmful movements) than if it did not have that type of feedback.
Keep at it, you'll recover!