How successful were the domestic policies of Napoleon?
This depends to some extent on how you would define success.
Napoleon would likely have defined success as keeping himself in power. His major goal was really a personal one rather than a political one. Looked at from this point of view, we would have to say that Napoleon's domestic policies were a failure. Napoloeon was popular when he was winning wars, but once he lost wars, he lost power in France as well. This implies that his domestic policies were not popular enough to keep him in power.
We could also say that Napoleon's domestic policies needed to advance the cause of the Revolution if they were to succeed. Napoleon called himself the defender of the Revolution, so we can say that his policies should have been aimed at maintaining the values of the Revolution. Here, the record is mixed. Napoleon did reduce the power of the First Estate and broke down many of the barriers between the Second and Third Estates. This is consistent with Revolutionary goals. However, he took more an more power to himself, which is not.
For these reasons, it would be very hard to say that Napoleon's domestic policies were a success unless we define success in some other way.