I have to say I agree with these comments. A lot of the safety issues I have found relate to riding as a group. When I am solo, I have a particular approach to stop signs/lights which is very effective for me. I assertively yield to any car which might conceivably have the right-of-way over me, and then I go (usually without completely stopping). In other words, I wait my turn. I feel, however, if I took this approach when I am part of a pack, I would pose a hazard to those piling up behind me (especially if I communicated that a driver should proceed while someone whizzed by me). Plus, we would tend to stretch out ridiculously at intersections. A lot of other interactions are also complicated by being in a group. For example, last weekend's encounter between CE and a dog. The dog was in the center of the pack, and CE was in the center of the pack, and there was really no way for CE to take evasive action without taking out those around him.
I don't know any solutions to these issues, they're just things that jump out at me, coming from my background of riding solo most of the time. I will say I am impressed by the way BBC members will call out street obstacles (like potholes). On the Hilly Hundred, for example, this sort of communication can be quite spotty.