No laws were nailed to the cross. In Matthew 27:37, they nailed a handwritten ordinance to Christ's cross that announced the charge that was a against him, which fits perfectly with the concept of the handwritten ordinance that listed the charges that were against us being nailed to Christ's cross instead and with him dying in our place to pay the penalty for our sins, but has absolutely nothing to do with nailing any laws to the cross. The reason why Jesu went to the cross was not in order to free us to do things that the Law of Moses has revealed to be sin, but to free us from sin. In Titus 2:14, it does say that Jesus gave himself to free us from the Law of Moses but in order to free us from all lawlessness and to purify for himself a people of his own possession who are zealous for doing good works, so the way to believe in what he accomplished through the cross is by becoming zealous for doing good works in obedience to the Law of Moses (Acts 21:20).
In Colossians 2:11-13, it refers to them as having circumcised hearts and people having circumcised hearts only refers to them being doers of the Law of Moses (Deuteronomy 10:12-16, Romans 2:25-29) while people having uncircumcised hearts only refer to them not being doers of the Law of Moses (Jeremiah 9:25, Acts 7:51-53). In Colossians 2:16-23, the Colossians were keeping God's feasts in accordance with the example that Christ set for us to follow, they were being judged for doing that by pagans who were promoting human precepts and traditions, self-made religion, asceticism, and severity to the body, and Paul was encouraging them not to let anyone judge them for obeying God. Those promoting asceticism and severity to the body would be judging people for celebrating feasts, not for refraining from doing that.
No.
None are. All of God's righteous laws are eternal (Psalms 119:160). In Matthew 5:17-19, Jesus specifically said that he came not to abolish the Law of Moses and warned against relaxing the least part of it, and in Romans 3:31, Paul affirmed that our faith does not abolish the Law of Moses, but rather our faith upholds it. Instructions for how to embody God's righteousness can't be abolished without first abolishing God's righteousness and the same is true for the other character traits of God that the Law of Moses was given in order to teach us how to embody.
No laws were made void.
I'm not.
God's feasts are foreshadows of what is to come and we should live in a way that testifies about the truth of what is to come by following Christ's example of celebrating them rather than a way that bears false witness against the truth of what is to come, so Paul was emphasizing the importance of now allowing anyone to prevent them from obeying God.
The Bible does not use the Greek word "dogma" to refer to the Law of God.
In Ephesians 2:12-19, Gentles were at one time separated from Christ, alienated from Israel and strangers to the covenants of promise, having no hope and without God in this world, which is in accordance with Gentiles at one time not being doers of the Law of Moses, but through faith in Christ all of that is no longer true in that Gentiles are no longer strangers or allies but are fellow citizens of Israel along with the saints in the household of God, which is in accordance with Gentiles becoming doers of the Law of Moses. In Ephesians 2:10, we are new creations in Christ to do good works, so it wouldn't make any sense to interpret Ephesians 2:15-16 as Christ abolishing his instructions for how to do good works.