2. The term "God hides His face" does not mean God has blinded Himself. He still sees what is happening. He can still hear if people repent. It means that God takes away His Hedge of protection from around the person so that they are allowed to suffer some of the consequences of their sins.
3. God doesn't hide His face from Born again believers because they have the Holy Spirit in their hearts and that guides and leads them. There may be times when we are tested, but God warns us of those times before hand.
4. He hides His face from unbelievers who say they don't need Jesus or the Gospel. They believe they can earn their way to heaven through their own works (common theme in Buddhism, Islam, the Pharisees and some Christian circles)