I would say declarative because its a statement.
It is C/3rd in row because thou meaning you, shalt meaning shall, and pangs meaning pain.
It crushed the ants body and legs
Okay so, you didn't include a screen shot or anything of what the text is, so I tried my best to answer your question without it.
There may be no land at the North Pole due to the fact that it could just all be ice that's floating atop the Arctic Ocean. Over the past few decades, scientists have discovered that the ice is thinning, therefore the likeliness of land beneath it is not great.
I think it might be a predicate nominative. Since there is already an adjective and this is just the follow-up and the last part of the sentence.
Hope this helps! Good luck!