Because certain religious groups consider pork to be unclean seeing as how it comes from pigs.
The story is told in strict first-person narration
I believe what this passage foreshadows is that C. Rome will suffer danger and destruction.
You can see in the excerpt that no good things are happening - there is a fire, and something is burning, and people are afraid - so obviously, it doesn't mean that it is going to prosper or be renewed, when something so terrible is happening. One slave cannot destroy an empire, which is why that is incorrect too.
