Should European newspapers have printed the cartoons of Muhammad? I say no, and for a very simple reason. Muslims do not depict Muhammad, in any way, shape or form. Any depiction of Muhammad is considered blasphemous, so I see no reason to create them.
I know that we have freedom of expression. I am free to insult and offend, but it is freedom that I choose not to exercise.
Writers or artists can express their opinions about the role that Islam plays in politics without resorting to means that they know will cause ill will. Anyone who wants to debate suicide bombing or terrorists who kill in the name of their religion should do so. It isn't true that we have to decide between speaking out or demeaning religious belief.
I would not riot if Muslims depicted Jesus in a way that I found offensive and it is terrible that demonstrations have resulted in deaths. I am a Christian but I acknowledge that much of religious belief is metaphor about the human condition. I wish that people weren't dying over metaphors about Muhammad or any other religious figure.