The law considers denying of the holocaust as an
insultation
of the dead. Insulting someone is not protected by the right
of free speech, AFAIK that's the same in the US.
No, it's not. Insults are speech too, and often hig art.
We protect them too, and rightly so. As our supreme court
said said, "If freedom means anything at all, it means
freedom for the thought we hate."