2. I know many ideologies that most people would consider "intolerant" but would fall under the "tolerant" umbrella because there's a rationalization for its intolerance. In fact, any ideology, as violent as it might be, can be rationalized.
While it is also technically possible to discover the underlying, hidden 'intolerance' of an ideology, society at large is not capable of doing that, simply because moral issues are some of the most complicated questions in the world.
We would never achieve a consensus about the underlying tolerance/intolerance of ideologies, because if we could do that, we would have already done it and we wouldn't have this problem in the first place.