I follow the traffic laws as best as I can manage when driving either my car or my bike. I do this for safety and to set a good example, as well as to protect my integrity in the eyes of the police, city employees, and students I've worked with on cycling safety and enforcement issues.
I've had no traffic tickets for decades now (last one was at age 18 or so). I've never been in a car-car or a car-bike crash.
I'm lucky that the traffic laws here don't discriminate against me in a way that would require me to break them for my own safety. The law here allows me to ride in the middle of the travel lane or ride outside a striped bike lane whenever I see fit to. If the law prohibited me from using the center of the lane I would probably violate it frequently and hope I didn't get stopped.
Group rides have been a source of frustration for me, however, when they roll through stop signs at speed. If I find myself in the middle of a pack on a large group ride, I create a hazard if I stop and nobody else does (and they don't). I try to get out of the pack so I can stop, but this is often difficult. On rides that I lead, I stop at stop signs, and encourage other participants to do so, with mixed results - some cyclists won't stop after gentle encouragement and I don't want to be heavy-handed or start arguments. Fortunately, the vast majority of my cycling miles are solo or with my kids.