For raping, in countries which claim to follow Islamic rules, they will get a death sentence, obviously, stone to death.
Things are not that simple. Rape laws in many of the Islamic nations are biased against the victim. Most of the times, it is the victim who is punished, not the perpetrators.
I have seen some reports, so I thought that's how it is in such countries. However, if what you said is true, why do they claim they are following Islamic rules?
And yes. It's not easy to get a death sentence especially in a democratic country. Many people will cone with human rights flag if a death sentence is given.
I referred to "Kill them all" in terms of action on the battlefield and with the methods of war only.