Yeah, I am not sure what this has to do with anything. I am aware of no one who is asking Abraham to send the saints to us so they can warn us of what awaits in the afterlife if we do not repent.
I am, however, aware of people who ask the saints to pray for them; knowing that if the prayer is granted, it is God who granted the prayer, not the saint. If a miracle is worked, it is understood that God works the miracle either directly or through the saint----not the saint himself or herself.
No; being God does not merely mean hearing the prayers of many people at once, being God means being eternal and all powerful.
Separated? Perhaps; but it does not follow that the "separation" is impossible to breach. The bonds of love do not unravel with death.