I have never found any reason to think that the stuff about God not respecting persons meant anything more than that he does not respect the status of individuals as understood in earthly or carnal terms. A king kneels as does a street-sweeper as does a derelict before the throne of God.
But I do not think that Moses and Elijah were not in some sense greater than, say, Esau, or that Paul was not greater than Epaphroditus. It wouldn't be wrong in my view to value the spiritual counsel of a pastor more than that of a derelict in the gutter, though both might have placed their trust in Jesus and be saved.
When James says the the effectual fervent prayer of a righteous man availeth much I think if he meant to say “of any saved Christian” he would have. As it is he seems to me to say that some Christians are more righteous than others, despite their all being justified before God.
When the Church declares someone a saint (”conferring” is imprecise speech) she declares that the person is a heroic exemplar of the saving work of God. Of course, the “saint” in question doesn't “need” the title. But those who think that John Paul II or Mother Theresa were heroic exemplars are comforted in having that opinion agreed with.
I don't understand the question about the “purpose” of or “need” for saints in the Church. Certainly the “saints” I feel close to serve as spurs for me to devote more time to prayer and works of mercy. Other “saints”, for whom I feel no especial ‘tug’ still spur me to praise God for His glory shown in transformed lives and still encourage me to hope that God might do great works through me.
It seems to us that star differs from star in glory, and that not only does God seem to make some people spectacular examples of what He can do and does do in the lives of all the redeemed, but, more than that, they show how God has shared so very much with us and has, so to speak, “constructed” his Mystical Body to meet the social needs of humans, who are gregarious animals.
In our experience, there is a dynamic in the life of Grace. We grow in faith, by God's unmerited gift. I know of an atheist in the 1800’s who went from skepticism bordering on cynicism to profound faith, from a dilettantish and comfortable life to an evangelical ministry among the Jews in Palestine. But such sudden and complete changes don't happen to all of us. We journey on over sunlight peaks and through dark and dank valleys.
We are strengthened by the society of all the holy ones as we travel. Sure God can comfort us anyway He wants. But in our experience one way He has chosen is the prayers, witness, and fellowship of the holy ones on earth and in heaven.
This is not intended to prove anything but rather to present answers to your questions.
Trying to get to my administrivia and out the door to class . . . that one will have to wait. Good effort, it appears.
I don’t disagree with anything you posted there.
The question remains. Why the sainthood? For what purpose?
They can be recognized for the exemplary lives without having titles added to their names and without prayers being said to them.