1. Brings us back to the bottom line: Do not talk to the police.
Clarification: This does not mean you cannot respond to a friendly greeting. It does mean that you should not respond to additional questions, such as, "Where do you live?", "Where are you going?", etc., etc.
2. Open Carry may be a political, educational, or social statement, but it is, first and foremost, a defensive tactic. Deterrence is always defensive.
While I cannot speak to every state's law, I do know that case law in my state specifies that concealed carry is an offensive tactic and describes it as an "evil practice". Reid vs State, Alabama Supreme Court, 1840