One way I describe the Empire in the RPJ Sci-Fi rulebook is that it is somewhat xenophobic, but that xeno- has long since ceased to apply to non-Greek humans. Varouforos is chummier with aliens than normal for nominal Imperials.

One of the things which makes the Empire all but unmanageable as a polity is its calendar system, or more correctly its calendar systems. The Orthodox Church prefers the Julian calendar, while the Temples of the Pantheon use a lunisolar version which has little meaning away from Homeworld but nevertheless remains popular.