The correct answers are:
Mutual dependency
and
Keeping information secret
Rationale: Dependency increases stakeholder power and creates risks and constraints. A buyer would not necessarily want a supplier to be dependent on its business (for ethical reasons), any more than it would want to be dependent on a supplier (for bargaining and supply risk reasons). The other three are clearly desirable.
Pitfalls: You may have hesitated over information-sharing, because of intellectual property and confidentiality issues - but it is necessary for high-interest, high-power 'key players'.
