1. If you were there would you have personally participated in those killings or would you ignore the commands?
This is a leading question, and one designed to cast judgment on the ancient prophets without a sufficient background of context. I personally detest the taking of life, but if one fully recognized the debauchery of the nations so condemned, one might have a completely different view. First, I'm not a soldier, nor have I ever shed the blood of man. But those who received these commands were trained soldiers. The wickedness of these cultures was such that it offended the sensibilities of the Israelites and their God. These cultures killed their own infants in much more terrible ways than the Israelites, and they weren't just competing societies. They represented the bottom of the barrel of human barbarism, depravity, decadence and savagery. They delighted in the murder of their families and infants. So I would have to be there, in the context of the times, to answer this question.
2. Would you personally take out your sword and run it through the belly of a pregnant woman the way your god commanded?
See Question 1. Also, keep in mind that killing isn't ending the existence of a person or animal. People and animals have spirits which survive the death of the body. In some situations, a person is better off being spared the pains of life, the plagues, famines, droughts and other aspects of human life. But just because they would be better off doesn't give a person the right to dispatch them by the sword. That command would have to come from the Lord. When the children of Israel sinned in worshiping the golden calf, Moses separated the rebellious from the obedient, then ordered the obedient to slay the rebellious, even if they were friends or family. By then the powers of God had been so thoroughly manifest through Moses that there were no mitigating factors for those who refused to serve God.
3. Would you have crushed in the skull of your child that was disrespectful to you?
No, but then, this was never commanded or condoned.
As one Old Testament scholar explained:
A good example of the way the Mosaic Law was administered can be found in the provisions for dealing with a dissolute, disobedient and obstreperous son. Here, certainly, it would seem harsh to impose the death penalty, and so it was. Yet, every son of Israel knew that it was a most serious offense to rebel against parents because it was a capital offense. At the same time, the law required parents to exhibit the utmost patience with a rebellious son and try to work with him in order to overcome his evil ways. This is evident from the fact that before parents could declare their son anathema, the following was required of them:
"If a man have a stubborn and rebellious son, which will not obey the voice of his father, or the voice of his mother, and that, when they have chastened him, will not hearken unto them; then shall his father and his mother lay hold on him, and bring him out unto the elders of his city, and unto the gate of his place; and they shall say unto the elders of his city, This our son is stubborn and rebellious, he will not obey our voice; he is a glutton, and a drunkard." (Deut. 21)
At this point the parents had to pick up a stone and be the first to strike their son down. No wonder we have no record of this procedure ever being used! Parents, no matter how provoked, would be extremely unlikely to resort to such desperate measures. Nevertheless, the provision in the law had an important psychological value. It impressed upon the youth of Israel that their parents did have the legal power over their very lives if they became violently rebellious. (Skousen, W. Cleon, The Third Thousand Years)