Name: Utopia. Nice and neat. No cheese or melodrama.
Flag: I'll have the people come up with it. I'm a ruler, but I don't want to be mass hated. So they will have a flag drawing contest. They will submit the best 25 to me, and I will choose.
Clothing: Same as usual. Although, there will be nothing covering your face. Hats are fine, but at max, nothing is permitted to cover a 3rd of ones face.
Language: Any language. Because my plans involve a lot of cultural murder, so I might as well let them keep their own language.
Anthem: The people will make a grand, dark, orchestral piece. No words would be spoken in it though.
Seems pretty lame and boring, but you're not asking the right questions. I'd have a lot of other plans that would most likely raise a few, if not, a whole shit load of eye brows.