I've read many accounts of the first century. Christians both avoided service and served in the Roman army.
Jesus acknolwedged Matthew, a tax collector. I think collecting taxes certainly makes you a government bureaucrat. A very dislike govt. official.
I studied the Ten Commandment provisons for whether it is const'l to have a public display of the Commandments. A lot depends on whether the text is present or shown by symbols. One of the problems with showing the text is that Jews, Catholics, and Protestants have different texts of the commandments. I confuse the groups but one has "Thou shalt not kill" and another "Thou shall not murder." There are strong theological differences based on the wording. So if the government lists text, the govt. is choosing a specific religion.