If the ball completely crosses the goal line, between the goal posts and under the cross bar, during active play then a goal is awarded. This is true even if the goal keeper is holding or touching the ball at the time.
A goal keeper is allowed to touch the ball with their hands when the ball is inside their own penalty area. If a goal keeper does so outside of the area, then a direct free kick is awarded to the opposing team.
As long as the ball is inside their penalty area a goal keeper may handle the ball. The position of the ball is important. The position of the goal keeper is not.
If a defender passes the ball with his feet to the goal keeper, the goal keeper may not touch the ball with their hands.
Yes. Only the location of the ball is used to determine whether the touch is an infraction.
No.
Not always. A goal keeper may not touch a ball with their hands if it was directly kicked or thrown-in to them by a team-mate.
a goal keeper saves the ball and the goal shooter shoots the ball
The goal keeper defends the ball from being in the goal.
No, the keeper cannot pick the ball up after his own player intentionally plays it to him using the feet.
No. The goal keeper may only touch the ball with their hands in their own penalty area.
There is no law about passing a ball backwards to the goal keeper. Direction is completely unimportant. If a player makes a pass with the foot to their own goal keeper, in any direction, then the goal keeper may not touch the ball with their hands. The consequence is an indirect free kick restart for the opponents where the goal keeper picked it up. A deflection would not be considered such a pass. It would have to be a deliberate play by the defender.
Yes.