As far as NBA rules go, yes. If a ball is touched after it has touched any part of the backboard above ring level, it is considered goaltending regardless of whether the ball is on its upward or downward flight. If the ball touches the backboard below ring level and is touched on its upward flight, it is considered goaltending; downward flight, no goaltending. Of course, the official also has to rule that the ball would have had a chance of going through the ring for goaltending to be called.
It's off the defender who blocked the shot.
No, it is not considered out of bounds if the ball hits the side of the backboard. Unless it bounces off the side of the backboard and then out of bounds before you or someone else can catch it.
when someone shoots and a person on the other team hits the ball, when the ball is on the way down
When a player throws the ball onto the backboard and a person catches it after it hits the backboard
Yes, it is. As long as the ball does not hit the back of the backboard or the shot clock, the shot is valid.
Only if your the person who did not shoot the ball
No if it was airball and nobody touched it it would be traveling. Once it has it the backboard its anybody's ball.
If the ball goes off the rim and over the backboard then it is out of bounds. If it goes off the rim and hits the top of the backboard but falls back in play on the front side of the backboard, then it isn't out of bounds.