To answer your first question, it depends on the levels and type of radiation. Organisms can with stand lots of alpha radiation for different reasons, hair, skin, sweat. Beta radiation can penetrate through hair and skin but not get down into the innards. Gamma goes all the way through. Depending on how strong the source is and the type is how long you can be exposed. The are some good articles about K-19, a Soviet sub that had a leak and hiw it took time for the radiation sickness to take effect.
To contribute to your thought about the government creating fear, the pawns, media and entertainment, do plenty of fearmongering . Most of our fears come from almost propaganda grade movies and TV shows. My opinion is the Simpsons did a good job of making sure that people are afraid of nuclear power and the radiation.
Edit:
My apologies for answers more technical than philosophical, I have been trouble shooting issues since Friday and I took the wrong approach to your blog.