Hi,
First of all I must say I'm quite surprised by Germany's move. They are usually very sensitive to these issue for known historical reasons.
Germany should allow people to practice their religion as long as it doesn't pose a threat to the public. If there were to be a religion that would believe in killing people would it be legitimate? Perhaps one would say as long as they don't practice it it's OK, but what if they simply preach this belief? Would it be fair to stop them?
These are difficult questions cause they lie right on the border between freedom of the individual and the safety of society.
In general I would say Germany is wrong in its actions but I don't think freedom of speech is limitless.