I have been reading through this and firstly, I am happy your chin didn't get shocked when chewing on the cord. My chin actually had reached through her playpen and got a hold of a cord from a fan we had in a window. She chewed the heck out of the cord, several inches long and down do the wire. I hadn't realized the cord was damaged until after the fact, but I was lucky because Tinkerbell never did show signs of getting shocked or burned or impacted. I am so careful now about how close anything, especially wires are to the cage.
It also sounds like your chin is eating and pooping fine, although some of us feed our chins acidophilus regularly to aid in digestion.
If your chin's paw isn't broken, and if he isn't chewing on his foot, it will most likely be ok and is just sensitive right now. Just continue to watch that it appears to be getting better, not worse(using it more rather than less) and that there are no signs of infection.
Keep us posted on how your chin is doing! Good luck!