Yes, religions tend to be bullies, Blasphemy seems to have come through Judaism to Christianity, and then in modern times Islam has used it too, as the Koran doesn't punish blasphemy.
Blasphemy is "do what we tell you and think how we tell you to think or we'll beat you up, or kill you". Ireland threatened to charge Stephen Fry with Blasphemy recently.
So, Islamic right wing extremists are the same as any other right wing extreme of any other religion, or non-religion.
For you to put Islam ahead and the "progressives" next seems to be nothing more than what is convenient for you. I disagree with your classification of the worst, however such people exist in all parts of life, left wing, right wing, religious, non-religious etc. It's a thing PEOPLE do, not just particular groups.