A little late to the thread with my 2 cents... Pace lines take a lot of practice! I remember when I first tried, I'd focus on the wheel in front of me. It took quite a bit of practice to start looking at the bum in front of me to judge distance to the bike in front and to look past the person in front to scan the road ahead. At any rate, it demands a lot of concentration. Now I have moved to DC and the groups I have joined don't pace line at all, it's just group riding.

Learning how to be smooth also takes time: not only communication, but smooth pedaling. I learned to sometimes touch the brakes while I continue to pedal. There's nothing worse then being behind a person that pedals and coasts, pedals, coasts... That's a bad wheel.