No 5 is very important. Police rely heavily upon the "consensual encounter," where they walk up to a person on the street or in a parked car. It always starts out the same way: "Hi, how ya doin' tonight?" Very quickly, though, it advances to: "You have anything illegal on your person or in your car?" And it goes downhill from there (for you).
Your response to the initial, "Hi, how ya doin' tonight?", should be: "Just fine, officer. And now, if you will excuse me, I will be on my way." And you promptly proceed to GO on your way. If the friendly officer says WORD ONE to you after that, your next statement should be:
"Officer, am I free to leave or am I being detained?" You can't lose that one. If you are free to leave, you are free to leave - and should. If you are not free to leave, then you are being detained, and there can be no further conversation absent a Miranda warning. If that's the case, do not waive your Miranda rights and refuse to talk to the officer. If he detains you and does not give your Miranda rights, don't talk to him anyway.