The Prophets you say didn't call him Father and G-d never referred to himself as Father to them because he wasn't their father as they weren't the Son.
Jesus referred to him as the Father because he was the Son.
Why does he say Our Father?
Because we are invited into that Union:
"I am the vine: you the branches. He that abideth in me, and I in him, the same beareth much fruit: for without me you can do nothing."
John 15:5
Again, Jesus says that without Him, union with the Divine is impossible. So either the God does as he's told by Jesus, or Jesus is Himself a God — or that He is the Incarnation of the One Divine.
"I and the Father are one."
John 10:30
Seems to answer that question.
You stated G-d asked us to refer to him as the Father. That was thru Jesus.
And nowhere else.
So in trinitarian thought Jesus is G-d, so every time Jesus is talking it is G-d talking? If not how do we differentiate from when Jesus the Son is talking and G-d the Father is talking thru Jesus
The distinction is in the correct determination of when Jesus is telling us something of the Divine nature, or something of the human nature. The Incarnation is the Union of the Two Natures.
The implicit answer is, when in doubt, look to Tradition, which is belief tried and tested in and by the community. But tradition is now a bad word, so man is adrift and left to his own devices. He is obliged to assert either his own infallibility, or at least his own superiority over all other interpretation. Or he's just flailing in the dark, but that its better to believe his own imaginings than the testimony of his forbears.
Father please take this cup from me? This is G-d arguing amongst himself as to the best path of his incarnation on earth??
Who witnessed these words? The apostles with Him were some distance away, and asleep. So where did the text come from? Either by word of mouth from Jesus, in the period after His Resurrection, and before His ascension, or by the inspiration of the Holy Spirit, when the scribe came to write his testimony.
....and does the Holy Spirit get a word in edgewise there someplace?
"But the Paraclete, the Holy Ghost, whom the Father will send in my name, he will teach you all things and bring all things to your mind, whatsoever I shall have said to you."
John 14:26
In Catholic and Orthodox doctrine Scripture is the word of the Holy Spirit. We go further and say only in the Spirit can one know Christ, for the Spirit leads us to the truth of Christ, and only in Christ can we know the Father.
Further yet — the Spirit affirms the infallible transmission of truth in Scripture, and likewise the Spirit affirms the infallible transmission of truth in Tradition. That's my belief, obviously, but it's what I believe, and it is neither unreasonable, nor illogical.
It might be worth noting that no doctrine has ever been promulgated by the Church for its own sake. A history will show that doctrine is a statement in a defence against error — the error was there before the doctrine — the only counter to that aargument is that error is as valid as truth.
Thomas