For some reason, it took me a minute to realize Rick had earphones in his ear. I would have never known the song as C&W is not my thing.
I did watch the episode again tho yesterday just to see if I missed anything. As far as the Potter kid dying after drinking water, notice the very very first scene, Rick comes out and drinks water from the barrel. Don't know IF that means anything.

Yet the kid was sick before he drank the water.
Plus, with the dead pig I think something is in the food or water. Maybe something (virus) could be in the garden????? Just speculating.
The nutjob lady in the woods, to me was just that. Losing her husband/boyfriend sent her off. Not quite sure what her purpose was, if any.
TIS