If you watch the police documentaries - and i watch them all - you will see how often being told to calm down, or relax has exactly the opposite effect on the drunken numpty to whom the phrase is addressed.
Not really. Depends who's saying them. If my OH tells me to calm down....then I need to calm down. If the kids tell me to calm down there's a good chance I'd escort them out the room :-)
it depends how the person is saying it and if you really need to calm down. My ex used to say it if i so much as tutted at him and said For Funks Sake..... that used to really annoy me as i didnt need to calm down. The couple of times my husband has said it to me I've been pretty angry about something and he just said nicely please calm down..... that doesnt bother me as i know i need to....