No, actually they were not. The New Testament AT THE EARLIEST was only completed with the death of the Apostle John, ninety years after Christ died.
Yes, there were writings of all sorts circulating during that time...and later...not only the genuine "eventually recognized as Scriptural" writings but many "close but no cigar" writings. There was no definitive teaching as to which of all of those writings were "really Scripture"
At some point after 100AD the Church had sorted things out a bit, and the Canon was more or less stable. But that Canon itself was only arrived at by the Church's Tradition.
"So then, let me ask this: is any tradition which makes the law of God to no effect a valid tradition?
I have no idea what you mean by this.
"Is it possible, in any way, that in the totality of the Catholic Church's traditions there is one which likewise runs counter to the scripture?
No.
Even Paul was humble enough to admit that Christianity could be a fraud [it is wholly dependent upon the Truth of the Resurrection], and if so then the believers were to be most pitied for buying into the deception. [link]
(1 Cor 15:14-19)
And if Christ is not risen, then our preaching is empty and your faith is also empty. Yes, and we are found false witnesses of God, because we have testified of God that He raised up Christ, whom He did not raise up; if in fact the dead do not rise. For if the dead do not rise, then Christ is not risen. And if Christ is not risen, your faith is futile; you are still in your sins! Then also those who have fallen asleep in Christ have perished. If in this life only we have hope in Christ, we are of all men the most pitiable.