The dead are either in heaven with Christ beholding God's glory or in hell condemned by their sins. Either way, our prayers make no difference as to their destination. They are already there.
Likewise, we are not to pray to anyone other than the Trinitarian God of all creation. To do otherwise is paganism.
He burneth part thereof in the fire; with part thereof he eateth flesh; he roasteth roast, and is satisfied: yea, he warmeth himself, and saith, Aha, I am warm, I have seen the fire: And the residue thereof he maketh a god, even his graven image: he falleth down unto it, and worshippeth it, and prayeth unto it, and saith, Deliver me; for thou art my god. They have not known nor understood: for he hath shut their eyes, that they cannot see; and their hearts, that they cannot understand. And none considereth in his heart, neither is there knowledge nor understanding to say, I have burned part of it in the fire; yea, also I have baked bread upon the coals thereof; I have roasted flesh, and eaten it: and shall I make the residue thereof an abomination? shall I fall down to the stock of a tree? He feedeth on ashes: a deceived heart hath turned him aside, that he cannot deliver his soul, nor say, Is there not a lie in my right hand?" -- Isaiah 44:15-20"Then shall it be for a man to burn: for he will take thereof, and warm himself; yea, he kindleth it, and baketh bread; yea, he maketh a god, and worshippeth it; he maketh it a graven image, and falleth down thereto.
And of course God is limited by your concept of time, right?
Again you reject life after death and the Communion of Saints.
There is nothing in Isaiah 44:15-20 violated by Catholic teaching.
You contradict yourself, though, for who are you to take the place of Christ, the sole intercessor between us and God?