The people who do the work. They know it best. Awareness and tools, obvious. Japanese aren't trained in teamwork. Have brief problem statement and mission statement, both in principle quantifiable.
Implementation is the genius of quality improvement teams.
Not if you want first-class results. If members of the team cannot because of their position, implement, then you have the wrong people on the team. It's called empowerment, and it's part of leadership. The facilitator remains neutral and somewhat aloof. Otherwise, managers and supervisors are hesitant to let people work on teams.