You apparently haven't read your Bible recently.
Jesus says:
[JESUS]For assuredly, I say to you, till heaven and earth pass away, one jot or one tittle will by no means pass from the law till all is fulfilled.[/JESUS] - Matthew 5:18
http://www.biblegateway.com/passage/?search=Matthew5:18&version=NKJV
Not all has been fulfilled, heaven and earth (last I checked, have not passed away.
Jesus nullified it to his chosen and basically warned that it would remain by the Father as a result of this world's nonetheless decline.
Paul says (you don't reject Paul, do you?) that the law is good if one uses it lawfully.
By "chosen," do you mean the Nation of Israel, the Elect Lady?
You don't have any business contributing to this world's punishments-
Sure we do.
Jesus said to "judge with righteous judgment."
That includes using the law.
Christ was crucified, what makes you think he supports crucifixion_
The law says (or, in the case of America's laws,
should say or at the very least resemble):
‘Whoever kills any man shall surely be put to death.Whoever kills an animal shall make it good, animal for animal.‘If a man causes disfigurement of his neighbor, as he has done, so shall it be done to him—fracture for fracture, eye for eye, tooth for tooth; as he has caused disfigurement of a man, so shall it be done to him.And whoever kills an animal shall restore it; but whoever kills a man shall be put to death.You shall have the same law for the stranger and for one from your own country; for I am the Lord your God.’ ” - Leviticus 24:17-22
http://www.biblegateway.com/passage/?search=Leviticus24:17-22&version=NKJV
Jesus said:
He answered and said to them, [JESUS]“Why do you also transgress the commandment of God because of your tradition?For God commanded, saying, ‘Honor your father and your mother’; and, ‘He who curses father or mother, let him be put to death.’But you say, ‘Whoever says to his father or mother, “Whatever profit you might have received from me is a gift to God”—then he need not honor his father or mother.’ Thus you have made the commandment of God of no effect by your tradition.Hypocrites! Well did Isaiah prophesy about you, saying:‘These people draw near to Me with their mouth, And honor Me with their lips, But their heart is far from Me.And in vain they worship Me, Teaching as doctrines the commandments of men.’ ”[/JESUS] - Matthew 15:3-9
http://www.biblegateway.com/passage/?search=Matthew15:3-9&version=NKJV
Doesn't sound like He opposes the death penalty to me...