I find the parallel between Moses, putting the baby in a basket and sending him downriver to escape death, fascinating. That does seem like more than a coincidence to me. Granted, it could be unconscious.
It's not. Being Jews it's been stated in a documentary that they crafted Superman off of what they knew best. As many artists usually do they speak with their background.
I want to say it's mentioned in the documentary Look, Up in the Sky