I have driven around St. Louis. Too many people don't understand the concept of keep right, pass left. Way too many left lane campers.
Big problem in Ontario too. Quebec is somewhat better in that regard. If you exaggeratedly stay in the left lane blocking traffic, you WILL get pulled over if a cop is around. Though I haven't seen it recently. Few people do it now. In the past, very often, someone would pull out to pass at a sane speed (say 120), having looked and seen nobody coming in their line of sight, when some jerk doing 140+ suddenly is on their tail, lights flashing. Though this too has toned down in recent years. Doing it now can get you an aggressive driving charge. And cell phones have helped a lot. You're encouraged (hands-free of course) to call in dangerous driving. Once I was being tailgated by a semi on the autoroute. There was no way out. A slower-moving pick-up pulling a large trailer was blocking the fast lane and other traffic in the right lane. The semi was so close I couldn't even see his bumper, and he periodically flashed his lights. After it was safe to pull over, I noted the name of the company on the cab of the tractor, it was a local gravel pit operator. I called the police, and gave them the info. When I got home a nice officer called me and said that they had a chat with the company's owner, and the owner in turn chewed out his driver reminding him whose name was on the side of the truck. The cop asked if I wanted to press charges. I declined, I told the officer that I'm sure his uncomfortable time with his boss taught him a good enough lesson.
I got a chuckle out of your comment about not being responsible for other peoples' stress, only your own. I agree that driving with common sense is good, but never assume that something you are or are not doing isn't causing someone else stress. I'm sure the doofuses driving around with ignorant bright lights on, and another set of fog lights on just to be cool, have no idea they are stressing people out either.
I've heard it said that in a monastery, there will always be at least one other monk that drives you crazy, and if no monk is driving you crazy you can be assured that you're driving at least one other monk crazy
That said there's only so much one can do. If someone on my butt gets worked up because I'm "only" doing 95 in a 90 zone, or I'm doing 80 because the car ahead is doing 80 and there's no safe place to pass, then it really is his craziness, all I can do is try to keep him from hitting me. This is deer country, and there's no guarantee I won't have to brake suddenly and hard to avoid one, especially at this time of the year when they're on the move, and at night (which is also why I have HIDs on my car).
We're all human and make mistakes sometimes, most, I hope, inadvertently. Some folks are just inherently bad drivers, like people who systematically signal their turn after they're half way into it, and there are some people who just don't give a hoot. Best is that one doesn't set one's expectations too high on the road, i.e. drive defensively.
I also avoid driving in packs like the plague. I don't like my safety being determined by the worst driver in the pack.
Oddly enough I've never ended up with opaque headlights or tons of stone chips on my hood...