I don't know what your group is like, but in mine there is a wide variety of skills. By definition, riding in a group means riding close. In the group I ride with, for example, we are often less than 12" apart, going up to 25 mph.
That means you have to develop safe riding skills for yourself, but also be acutely aware of the skills of the riders around you. Invariably, in every group there are one or two individuals who are ones you don't want to be close to -- they don't hold their line, they accelerate or decelerate very suddenly, etc. At the beginning of every ride, try to find out who those riders are, and stay clear of them. Often at the beginning of the ride, you're tempted to concentrate just on yourself and your ability to keep up. But keeping yourself safe is in the end the most important thing to do.
Group riding, including pace lines, are a blast, but they're not worth it if you end up with a broke collarbone because another rider caused you to have an accident, or if you did that to another ride because of your own carelessness.