yeeks!! Listen to Eden and some others.

half wheeling is really dangerous for the person in front and you!! During one practice ride, one of the less experienced rider half wheeled while trying to work on a pace line. The inexperieced rider's front wheel caught the skewer of the girl in front and the inexperienced riders bike "jumped". She ended up flying over the handlebar and ended in hospital.

Pace line can be an exilerating experience cause individually you can't go that fast and keep it up for many miles.

And definitly, learn to group ride really close to each other without getting spooked. If I sense you are bit nervous, it makes me nervous and I stay away from you.