If you believe in absolute truth (I do) then there is a perfect justice by definition. I believe God is that by nature. In order to meet a standard there has to be a standard and you have to hold to it. Otherwise "perfection" is meaningless. What you describe would be God acting arbitrarily, which He does not.

Jesus prays to the Father, that is not the same as worshipping the Father. The other poster answered your question about Jesus quoting a Psalm when He said, "why have you forsaken me?" Did you read the Psalm? It's very fascinating.

I didn't put God in a box. He laid out specific requirements for His people, which can be found throughout the Bible.

God can certainly do anything He wishes but in order to have the titles of good and perfect He certainly has to meet His own standard. A God who acts arbitrarily is not good or perfect.