Muslims consider the honor of the Prophet Muhammad to be dearer to them than that of their parents or even themselves. To defend it is considered to be an obligation upon them. The strict punishment if found guilty of this crime under sharia, the Islamic law, is capital punishment implementable by an Islamic State. This is because the Messenger Muhammad said, ‘Whoever insults a Prophet, kill him.’

All law is from God, not from man. So, all laws are derived from the divine text, or the Koran.

If someone dies as a child, they go to heaven. But, as an adult, he made a choice of accepting Christianity, so, that's not apostacy. If he was a Muslim as an adult, then changed, that would be apostacy.

Muslims consider the honor of the Prophet Muhammad to be dearer to them than that of their parents or even themselves. To defend it is considered to be an obligation upon them. The strict punishment if found guilty of this crime under sharia, the Islamic law, is capital punishment implementable by an Islamic State. This is because the Messenger Muhammad said, ‘Whoever insults a Prophet, kill him.’

Your choices make you whoever you turn out to be.

You cannot have more than one leader worldwide. So, you would only have one Caliph for all of the Muslim world, so whoever that is, he would have authority over all of the Muslim land and wherever the Sharia is implemented.

The penal code deals with things like theft, false testimony, adultery, fornication, etc. and then there's the law of the state, the law of the individual and the law of the public.