Suggestions
A suggestion box with votes, threads and an actual answer.
How it flows
A member runs /suggest. It is posted with up and down vote buttons and a thread for discussion, and given a number so people can refer to it.
Staff approve, deny or mark it implemented with /suggestion. The original post is edited to show the decision and your reason, and the author is sent a DM, the difference between a suggestion box and a bin.
Controls
You can limit who may suggest by minimum level or by blocking roles, and let members withdraw their own while it is still open. A withdrawn suggestion is deleted rather than left on display with a label on it.