God doesn't know jack. That is why he made us the way we are.
On Limbo, this was a painting in a man's mind. Nothing more. It doesn't exist.
All humans go directly to heaven except the ones that understand the 10 commandments and go against them.
No that makes no sense. Let's say that John and Bob rob a bank. They smash the get away car and John dies. Bob lives and goes to prison for 10 years. Right before he died, John repented of his sins. Bob repents too but still has to go to prison for 10 years. So both committed the same sin and both repent but John goes straight to heaven and poor Bob sits in jail for 10 years.
What makes much more sense is that John, before going to heaven, goes to purgatory where he experiences the jail time he would have had on earth. Then after he is cleansed and expiates his crime he can go to heaven and be with God. Purgatory can take place on earth or after death or both. It is a cleansing process...what some Protestants call the discipline of the Holy Spirit. Jesus paid the eternal price for our sins but when we sin we must be willing to accept the temporal consequences. No criminal would expect to let out of jail because he is born again in prison and sorry for his sins.
God knows everything. Even the number of hairs on your head.