Douglas - // I just need to check if that's the same free speech that forbids shouting 'fire' in a crowded theatre but allows any number of incitements to murder and maim in the name of an overgrown fairy of whatever flavour. //
Free speech does not 'forbid' shouting 'Fire!' in a crowded theatre.
The entire premise of Oliver Wendell Holmes Jr.'s ruling in a court case in 1919, is that the phrase is in fact "Falsely shouting 'Fire!' in a crowded theatre.
The word 'falsely' is often missed out, and completely removes the point that Holmes was making - the difference between a genuine warning, and malicious intent.
To shout 'Fire!' when there is a fire, is protected under the laws of free speech because it signifies a clear and present danger.
Falsely shouting 'Fire!' is not protected, because it causes danger of harm without justifiable cause.
// If it's used in a book, newspaper or comic it's 'hate speech' but dressed up as religious doctrine it's fine. //
That in my view is an unsustainably wide sweeping statement - any phrase or message has to be taken under its own merits, including the context, the meaning, and the intent behind it.