regarding cyclists - i don't know, you're probably right, there's nutters in every mode of transport -but i have a heavy pro-bike bias that's difficult for me to break out of. in my daily eight mile commute, i see car drivers pulling out, cutting me off, jumping red lights (it now seems 'acceptable' on the road for cars to jump the red by at least 3-4 seconds) - so its difficult for me to get a sense of perspective on cyclists doing the same, they may only be acting out a kind of misguided vengeance against their own transgressors. i jump the occasional red at 7am when no one's about, and only at traffic lights that primarily exist to regulate the flow of peak hour traffic - there are two such sets on my route - but that's about it. i guess unconfident cyclists are the main danger to motorists, because they are so unpredictable. if you assert yourself as a cyclist in urban traffic, claim your space (but not unreasonably), then motorists tend to feel more comfortable with your presence, and are less likely to treat you as a 'mobile obstacle'.
