"Religious practice" is not limited to ritual. Good deeds, helping the elderly, being honest, not stealing, the 10 commandments, sacrificing the goat, killing the cartoonist, etc are all part of religious practice. "Religious reasoning" exists in the Judeo-Christian tradition. The killing in this case is not justified through interpretation, rationalization, or reasoning. It is commanded by the final, uncorrupted word of God.
Edit: You also twisted my statement. I asked whether the freedom should extend to the ideology. You twisted it around and stated that the freedom does not extend to shooting people. You're hiding from the issue.
Regarding "shooting as a religious practice", well, not in the sense I understand "religious practice", that is, a regular ritual. If you're talking about "religious reasons", sure. Much in the same way that plenty of people have died for political reasons due to the actions of fringe movements, which in a democracy is not ground enough to ban the more mainstream version of these groups (eg, the actions of the banned left-wing Action Directe in France did not lead to the dissolution of the Communist Party).
As soon as extremists get involved things change. These murders have caused many people who were against publishing Mohammed cartoons to change their stance.
I'm not entirely sure why we coddle religious fanatics as we do, but it needs to stop for us to progress as a society.