Let me assure you that for every position, there is only one grade level in QP. The position you have applied to must be a position with grade 15. It does not matter what is your qualification and your nationality, you will be offered as per the grade of the position.

Regarding WIA, as far as I know, QP does not have it. However, it has what it is called as "currency protection allowance", and it varies depending on your nationality.