I think flag is probably not going to hurt.
Note that when people yell, honk, blow smoke, and spin tires at you, that means they saw you, which is a good thing. They are not trying to kill you, so they probably won't kill you, which is also good. Even the intimidation-passers are actually trying quite hard to *nearly* hit you, which means they are more or less trying to not hit you, which is a good thing.
So that's all good.
People texting, posting on FB or BF, watching videos, or chatting up with their friends and family will not honk, yell, blow smoke, or spin tires at you. They might not see you, which is bad, and they might kill you, which is bad.
On narrow twisty hilly roads, drivers actually need to spend most of their time looking out the windshield, which is very good for you. As opposed to straight flat wide roads, where they can and do spend a considerable amount of time not looking out their windshields.
In conclusion, don't fear unsocial angry people, and don't fear social people on twisty hilly roads. Fear (and avoid) social people on flat, straight, wide roads. That's where you're gonna die.