If anything you could say that questions 3 and 4 tie in together in the respect that the Colosseum is a visual representation of Roman gravitas. In terms of superiority it shows that the Roman Empire had plenty of resources, it shows that Rome prided itself on the entertainment and well being of its' citizens. You could say that the Colosseum is the Rolex watch on the wrist of the Roman Empire, it's a way of showing its' citizens and rival nations, "look at how much money and power we have." It was also an intimidating place, a place where prisoners of war and criminals fought to the death. So there was also a dominating feeling from the perspective of a prisoner, a feeling that Rome had them by the throat and there was nothing they could do about it.
