Let me not put too fine a point on it, then, if we're talking about blasphemy.
The Jewish religion explicitly denies that Jesus was the Son of God. That is blasphemy.
The Muslim religion also denies the divinity of Jesus. That is blasphemy.
The Bhuddist religion denies the existence of God as such. Blasphemy.
The Hindu religion actually accepts the full divinity of Jesus, but says that he came several times under different names. That's not actually blasphemy...but it is error.
You said: "It is wrong to depict any religious leader or icon in a way that will be interpreted as blasphemy by those who follow that religion."
If that is really true, then it is wrong to state the tenets of the Jewish, Muslim or Bhuddist religions at all, because they deny the divinity of Christ, because that is pure and utter blasphemy of the most fundamental, God-denying kind -not like making fun of Mohammed, but making fun of Allah or Yahweh directly.
Are Christians allowed to become offended by Judaism and Islam, whose MERE EXISTENCE is blasphemy?
Sure, they're allowed, but Christians who do get offended like that are idiots.
And so are Muslims who go hog wild because someone makes fun of Mohammed.
The proper response is to tell them to grow up.
And to tell them we will defend the right to freedom of speech with force of arms, instead of apologizing to their medieval sensitivities.