"Tears are going to roll" makes sense... But what is it about sheep?

that first rule would make it quite difficult ever to wash one's feet or treat any of the horrible conditions they might start to get due to lack of care, eg overgrown/ingrown toe-nails.

most of it is probably misheard. It's a bit notorious for having either incomprehensible lyrics, or nonsensical lyrics. At least in parts. The background singers are really hard to be sure what they're singing.