Members elect the board members to run the co-op as their representatives.
I'm not clear as to the checks you want to place on the board. On BIG decisions, we hold membership forums to get feedback from all interested. At the moment we're on the road to a new store and have held one member forum to explain why we need the store, to gather ideas, and to listen to anyone who wishes to object. IMHO, there are ways for members to be heard by the board if they feel strongly enough about an issue and ways to get things done without changing charters and bylaws. A few years ago in Minneapolis, several co-ops wanted to consolidate.