Yes that is a famous series with the puppers going underwater — love those photos

I’m a medievalist. It’s been accepted for years that fleas spread the disease, and one of the animals they travel on = rats (especially along shipping routes). Fleas, obviously, are tiny and hide in weird places (not just on animals) so the plague spread to even isolated villages etc as a shipment of cloth could bring in infected fleas

“is not worried to prove” is very awkwardly worded English

Yes, in true terms diamonds have zero inherent value (same as gold). They can be put to certain purposes outside of outrageous decorations for rich people (as in certain metals like copper while gold is useless)

Exactly. This is hardly a “new” idea in philosophy, especially if one knows anything about eastern traditions or h*ll philosophy before the 19th century