I think there is a shift at “...assured him”. From reading the beginning, you would think the person is under arrest, “stay where you are”. But, the sentence goes on to say that the police officer ‘assured’ him that. He could’ve been in danger, so the officer was telling him that help was on the way, just stay put.
Past; passed is the verb form; pass is also a verb form and a noun
I can't really answer unless I see the text.
In "Shooting an Elephant" by George Orwell, "the real nature of imperialism" is shown when Orwell says that as a British officer in Burma, he himself is against colonialism because in a job like that you see the dirty work of the British Empire. And when he faces the elephant he sees clearly that even though he doesn't want to kill the elephant, he has to because the Burmese expect him to, so he is not free. By limiting the power of the others the British Empire has limited its own freedom making a place of hollow power.