NAV - Responsibility Center

NAV will pick the default value in Responsibility Center in Sales/Purchase Doc. which base on the following info.

1st Priority - User Setup Card
2nd Priority - Company Information Setup Card
3rd Priority - Customer / Vendor Card

Once user create a SQ/PQ, the default Responsibility Center value will be assign base on the user card setup.
When user assign a Customer to the SQ/PQ it will verify the customer/vendor card again.

my problem: (i'm not sure this is the default setting or not, will update once i find out.)

1. User can choose a customer/vendor which not belong to his Responsibility Center Group. The system will prompt a MSG(inform wrong RC) but user still able to do SQ/PQ then make order.
2. User can change their own customer/vendor card Responsibility Center Group to others.
3. User can assign those customer/vendor card which have BLANK Responsibility Center to any others group.