This suggestion I (assume) is basic and would do a lot to filter out spam motions. It would need only one config point, require.Second, and if this is set to true;

1. Whenever a motion is proposed, it will say 'waiting for second',
2. If someone wishes to second a motion, they will type !second (motion id)
3. If a motion does not receive a second for 24 hours, it will be killed.