bobld,
The R.Catholics would not ostracize? Not so long ago, the Catholic church would ostracize from the land of the living. The only reason they don't have heretics killed now is because the secular states don't allow them to. Besides, doesn't St.Paul himself (1 Cor. 5:5) instruct Christians to throw the transgressor into fire?
Whenever, and wherever, a religion has actual power over its members (not only spiritual one), has usually dissenters and transgressors killed, not just ostracized. That was the case with the Hebrews in 'biblical' times, that was the case with Christianity throughout the Middle Ages, that is the case today in Islamic states, and that would be the case with JWs if they had real power.
Again: the only reason that christian religions don't execute people anymore is because they've lost political power.
So don't be carried away. All religions, ecpecially all of monotheism (which is a fanatical idea in its basis) are potential (and often, real) killers.