I have a banging problem with my RST..And I want to learn something..

1- What controls the boost on idle? Because I have 11 psi boost at idle.. I cant prevent it.. overfueling can do it?
2- I have banging at hard accelerating.. what does this?

Thanks for the help..

The car's specification..

1-13 psi boosted
2- PTS chipped ECU
3- Big intercooler..