Explanation please? (spoilers)

What an intriguing film, though I feel like I understood none of it. Spoilers ahead.

What was Haim-Aaron writing in that little notebook, with the pencil? It seemed very important to the plot, but was it ever explained?

What was the eyechart about? Was it ever explained what caused Yanke's toothache and headache? And then, were we supposed to understand that Haim-Aaron did not need glasses after his resurrection? (Although he did continue to wear them.)

In the one scene at the abattoir, where there was a large organ or hunk of something that they were vacuuming, and then said "don't worry about it, it's not kosher". What was that? A fetus? I would have thought that they did not slaughter pregnant cows.

What possible reason did Haim-Aaron's father have for letting all the cattle out into the fog?