hey i have many problems please help me !!!

i use steal button on keyboard but can't steal the ball why ?
pro hop and backdown button on keyboard?

i can't dunk normally , i press dunk button but players can't
dunk under the rim why? ( for keyboard and joystick)

most of the time i go forward with the ball but get offensive foul
with falling defensive player to the floor why?(what is the mistake?) *

and last one sometimes i can't shoot from a bit far with scorers
why? (they do * )

Steal is the layup button.

Pro hop and backdown can only be performed if you use a gamepad. If you're a stingy mofo like me and don't want to buy a gamepad then use PPJoy.

I don't know about the dunk thing. I think using the layup button is a better choice if you don't have any running momentum.

It's just you and you're forcing dunks/layups and you're being called for the offensive foul. Learn how to get around the player first, or if you want to pussy out then just adjust it with sliders.

Again, you're just playing badly. Practice shooting the ball.

please more explanation

I can't really explain it that much better than I just did. The last three questions were just questions on some basic things on gameplay that you aren't used to yet.

Look for a few threads that talk about back down in this section, they should have PPJoy or at least mention it. That's probably the only thing I can elaborate on (or at least that I feel on elaborating on at the moment).

Edit: Here, I did some of the work for you even.

http://www.nbaliveforums.com/ftopic42056.php <==Just look in here.