Lots of reasonably modern sounding public health rules about infectious skin diseases.
Commentators made a point of how leprosy spreads bodily corruption can be used as a metaphor for sin. But the passage doesn’t seem to do that.
There is no blame attached to it here, though by Jesus’ day there seemed to be strong assumption that lepers deserved or earned their fate. And of course Jesus turned this upside down by having more to do with lepers than the cleanest religious leaders.
But here it is a real honest to goodness diagnosis guide… I loved the bit about how a bald man is just bald and a man with receding hair just has receding hair.
The diet was a mix of symbolism and a reasonable nutritional and safety element, this seems primarily practical.