1. The "flaw in the imperative" represents the possibility for slaves to flee their "masters", abandon their captivity and live a certain freedom, because it represents a failure of white authority. Ridgeway is a Slavecatcher and believes that it is essential that this failure be decimated, because it gives slaves strength and hope and removes the sovereignty and superiority that whites should have over them.
2. The hope of freedom is dangerous because it allows blacks to have the chance to match up with whites and to destroy the entire system established in slave society. As whites saw blacks as inferiors, giving them the hope of freedom made it possible for them to be books, which made them the same as whites and this was seen as a way of lowering whites.