Yes, some roads are dangerous, no doubt about that. Personally I try to stay away from roads that allow passing, have vehicles moving over 40 mph and have little to no shoulder. On the other hand I'll ride those same roads if it's the time of day ( or night ) when traffic is very low.

Yep, I've had a person do that to me before and indeed that type of behavior is a great threat. The people who do that sort of thing are usually the kind of people that most law-abiding people will refer to as xxx-wipes.