I'd guess that your idea of an extreme conservative or a progressive is anyone who feels that conservativism is bad for society.However, in answer to your question, I believe extreme right-wingers are dangerous. I suspect that like most progressives, your idea of extreme conservative is probably quite expansive in scope and would include anyone that feels strongly that the progressive movement is bad for our society. Just a guess but I'd wager it is a good one.
Btw... you'd be wrong about my position. I'd want to see WHY they think that. If it's based on nothing but their own blind dogmatism, I'd dismiss them as irrelevant and extreme. If it was based on some of their own ideals and logic, I might disagree with them, but I wouldn't consider them extreme.
Perhaps instead of making silly all encompassing assumptions, you might want to attempt to LEARN something about those you debate.