You have to know which laws were nail to the cross and which ones were not.
None of the law was nailed to the cross.
If it had been, then that means it's been done away with, and Jesus told the Pharisees he had not come to abolish the law but to fulfil it.
Furthermore, if some of the law in Leviticus has been done away with but other parts haven't, then you are being selective and are certainly not obeying EVERY word which comes from the mouth of God.
Once you have that knowledge and understanding then you can apply the rest.
You can if you like.
These are the things one must do to set themselves apart from the rest, that don't know God, to be sanctify.
This is what the Hebrew had to do to set themselves apart from others - dedicate themselves only to the one, true God and keep his law.
I am not under the law; my ancestors were not the one who were given it and I was not brought up to observe it.
I have Jesus.
Refusing to eat a bacon sandwich will not make me holy or bring me closer to God. I have no chance of holiness without Jesus.
Buying up the entire stock of pork/bacon/ham/gammon from Sainsbury's and throwing it in the River Dee will not make me holy. I don't eat shellfish, and I am no holier than those who do.
Jesus fulfils the Jewish law that I was never under.
Jesus saves, not the law.
If the Israelites had been able to keep the law and the covenant God made with them, perfectly, it might have saved, they might have been an example as God's people and a light to the Gentiles, and there probably would have been no need for Jesus to have come. The Israelites were unable to keep the law they had been given. They broke it, and God's Covenant, over and over again - they had made an idol for themselves before Moses even came back down the mountain with the 10 commandments. Even Peter said that his ancestors had been unable to keep God's law, Acts of the Apostles 15:10.
God's covenant was frequently broken - not by God; by those who were supposed to be his people.
God's covenant, which was not given to Gentiles, was repeatedly broken, a new one was made, which renders the old one ineffective, and you even say that some of it was nailed to the cross. I think we can agree with the writer of the Hebrews that the old covenant has gone, cannot save, is ineffective and will soon disappear.
The new covenant is made on, by and centres around, Jesus.
The work of God is not to obey the law perfectly, but to believe in Jesus, John 6:29.
God's will is that we believe in Jesus and have eternal life, John 6:40.
Only Jesus gives eternal life, John 3:16, John 3:36, John 6:53, 1 John 5:12 - not Jesus + the law.
Only Jesus is the way to the Father, John 14:6 - not Jesus + not eating pork.
Only Jesus saves, Acts of the Apostles 4:12 - not Jesus + abstaining from certain foods.
Only Jesus has reconciled us to God, Romans 5:11, 2 Corinthians 5:18-19.
If we remain in Jesus we will bear much fruit which glorifies God, John 15:5, become new creations, 2 Corinthians 5:17 and have every Spiritual blessing, Ephesians 1:3. If we are in Jesus, not the law; Jesus, we can ask anything in his name.
If we do not come to Jesus and remain in him we will not have eternal life and will be cut off from God, John 3:36, John 15:6.
Jesus is all that we need.
Accepting a bacon sandwich will not defile me - accepting Jesus makes me holy.
Refusing to eat pork and shellfish will not give me eternal life, make me holy or be a witness which brings others to God - accepting Jesus, living in him and for him is what will make the difference. No sinner has ever been brought to God by the food laws, they come to God because of his amazing love, expressed in Jesus. No one has ever said, "I live a life of crime, doing drugs, drinking and beating up the wife - and I was made holy when I gave up pork". No one was ever made a new creation, given a new heart, forgiveness and eternal life by not eating prawns.
So I will leave you to your proof texts and your works. I'll let you explain to Jesus why his death on the cross is not enough, and to show the Father how you decided to improve on his Gospel of salvation.
Jesus is all I need. I'm sorry if the Son of God is not enough for you.
Goodbye.