On the first point, the government of the day would be open to selecting board members that it felt responded to the current needs of the board, given the kind of experience that was necessary to help the commissioner.
For your example of police experience, I think the minister has said that the government would look for some measure of police experience on the board, but it should probably be broader than just former police officers.
You will note that in the bill there is a provision that current members of the RCMP are ineligible, as are employees of provincial or municipal governments, so it will not be a board of serving police officers.
The board is free to provide advice to the commissioner in the form that it best sees fit. How they do that would be open to discussion between the board and the commissioner.
The deputy minister of public safety will serve as an ex officio member of the board and, in that sense, the minister is represented at the board, even when the minister is not present at the board.