SocketRocket
Ryder Cup Winner
Personally I don't take a practise swing - once I have warmed up before the first tee shot of the day, I don't feel the need for a practise swing. I don't see that anyone else, including you, needs to either.
Hmm! I like to make a practice swing so that I can visualise the shot I am about to make. It helps a lot especially if you want to shape the ball, it also stretches you out a bit. I don't think it's an unreasonable thing to do, most tour pros do it and it should only take seconds.