As to your second question, it is not necessary for a legitimate authority to make the application of that authority continuously subject to the consent of each individual. When a criminal is taken into custody, for example, the police do not have to ask him if he would mind terribly if the officer puts handcuffs on him. It is done against his will, and it is just. When decisions are made for the common good, there are always some in the community who may disagree with those decisions. Yet they are still bound by those decisions under the 4th commandment. An individual citizen of a nation does not get the opt out of any decision he chooses. Again, read those sections of the Catechism on the 4th commandment.