Freedom to say whatever you'd like with no repercussions short of calling for violence is certainly a western idea. Freedom from hate speech, for instance, is something one might like that you cannot find in the US. Without qualifiers "freedom" is a floating signifier.
A western idea in origin. According to the historian Tom Holland its a Christian idea in origin (read his book Dominion if you want an explanation) - does that mean atheists should not support it? its a good idea, everyone should adopt it.
No repercussions for anything short of calling violence is actually an American idea, to some extent other Anglophone countries. It is not generally accepted in continental Europe which has always had far more restrictions on speech. So its not generically "western". On the other hand some level of free speech is widely supported by many people in non-western countries. its in a lot of constitutions, and people will generally say they support free speech.
I'm not sure what you mean by "justice".