I see. So if you had a child you would support killing your own child. What kind of twisted love must someone have for their child to support killing them because they have dishonoured you?
lain:
I think this may be the most misunderstood law in the Bible. I've seen it misrepresented so many times as "If a child is disrespectful they should be stoned", and you're representing it as just "dishonor."
The conditions required in that law would essentially limit its enforcement to cases where no other method of discipline could bring the child to repentence. The law's very existance would make it nearly never enforceable. Especially in the type of society which would allow such a law to exist in the first place (which is very different than our own.) And even still, its not about "what I would want" to do.
Cannot God execute His own wrath upon evildoers?
Do not take revenge, my dear friends, but leave room for God's wrath, for it is written: "It is mine to avenge; I will repay," says the Lord. - Romans 12:19
God certainly can. The question is whether God created an institution to do that for him in this life.
Romans 13:3-4
For rulers are not a terror to good conduct, but to bad. Would you have no fear of the one who is in authority? Then do what is good, and you will receive his approval, 4for he is God’s servant for your good. But if you do wrong, be afraid, for he does not bear the sword in vain. For he is the servant of God, an avenger who carries out God’s wrath on the wrongdoer.
Most Christians take this passage as descriptive and simply use it to say that Christians have to obey their government pretty much always. But I don't think this interpretation fits with context, nor the parallel with Romans 12:19 that you mention. Christians aren't supposed to unilaterally take vengeance, this is true. But God did create government as an institution to do that for him in this life.
So, its not about "what God can do." I'd advocate not punishing any crimes if I thought that was what God would want. I advocate punishing the crimes I do because I believe that would conform to God's justice.