Let's be clear: I agree there is no justification whatsoever for gunning down journalists or cartoonists. I disagree with your seeming view that the right to offend comes with no corresponding responsibility; and I do not believe that a right to offend automatically translates into a duty to offend.
I wonder sometimes what it would be like living with the Dalai Lama - because, even though he's probably about the most saintly guy on earth, I'll bet he's got some really irritating habits. You know the sort of thing - hogging the TV remote control; stinking out the lavatory and not opening the window; constantly losing his keys.