Psalm 139 tells us, 'Lord, even before I say a word, you already know it.'
If God knows these things already, what is the point in saying them aloud?
Yes, God knows what we need. Yes, even before we ask He knows all.
Yes, God does not need to be TAUGHT what our need is.
Yes.
I think the reason He wants us to open up and speak and talk to Him is because of His central purpose. God wants to give us Himself.
We want things - this thing and that thing. We need that thing and this thing.
God knows we may need this or that. But His purpose and plan is to dispense Himself into us to be united with us. And in the opening up of our being He can impart not only things TO us but Himself as divine life into us.
If you believe that Jesus Christ is religious fluff you will have a hard time understanding this. Christ is not religious fluff. Rather
"all the treasures of wisdom and knowledge" are hidden in Him
(Col. 2:3).
Throwing open our hearts and out mouths to God facilitates God imparting Christ as the Spirit into man. And we can be made full in Him.