Q) I see you are carrying a firearm in the open, why are you doing this?
A) The Commonwealth of Virginia and the 2nd Amendment to the United States Constitution both guarantee that the people have a right to keep and BEAR arms, and I am just exercising that right, the same way YOU are exercising your 1st Amendment rights of free speech...
VA Constitution:
Section 13. Militia; standing armies; military subordinate to civil power.
That a well regulated militia, composed of the body of the people, trained to arms, is the proper, natural, and safe defense of a free state, therefore, the right of the people to keep and bear arms shall not be infringed; that standing armies, in time of peace, should be avoided as dangerous to liberty; and that in all cases the military should be under strict subordination to, and governed by, the civil power.
US Constitution:
Bill of Rights, 2nd Amendment:
A well-regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed.
Q) What are you, some kind of “gun nut”?
A) No, I'm just a citizen, who is concerned and responsible for my own safety and protection. The US Supreme Court has ruled that police have no duty or legal obligation to provide personal protection for individuals, so I'm just doing my duty as a citizen.
Q) What gives you the right to carry a gun around like this?
A) The US and VA constitutions, see "Answer 1" above. Self defense is a FUNDAMENTAL HUMAN RIGHT, the same as free speech, the right to practice whatever religion I want, the right to vote, or the right to be secure against unwarranted search and seizure.
Q) I am an LEO and I demand to see your VADL or CHP.
A) If I am walking, I am not driving and am not required to show my VADL. If I am open carrying and not concealed carrying, I am not required to show my CHP.
Q) I am an LEO and want to know what you are doing and where you are going carrying a weapon.
A) Under the 5th Amendment to the United States Constitution, I am not required to make any statement as it provides me protection against abuse of government authority in a legal procedure.
Q) I am an LEO and I demand you co-operate with my questions or you can be charged with obstruction of justice.
A) The Court of Appeals of Virginia has held that "obstruction of justice does not occur when a person fails to cooperate fully with an officer or when the person’s conduct merely renders the officer’s task more difficult but does not impede or prevent the officer from performing that task." (§ 18.2-460(A))
Q) This is City Property, you cant carry here.
A) According to Virginia Code § 15.2-915 I am only prohibited from carry in state or federal outlined areas, localities cannot make laws forbidding the carry of a firearm. The state of VA has established Preemption, and cities are actually prohibited by State law from making up their own laws restricting firearms ownership, transport, or possession.
Just a few of my own modifications. You're on the right track, but you need to temper the language. Some of your answers come across as a little abrasive and smart-a$$. Quote actual statutes. Quote the Constitution. Quote court rulings. But be careful about coming across as snide or snarky, and don't go so heavy on the "because I can" attitude, because it can sound rude and childish. Justify anything you say with quotes from the law or from court rulings. That makes it sound more official, and gives your position the weight of authority, rather than just sounding like some pouty "gun nut"...
Good luck!