Les héros sont-ils toujours moraux?

The answer to that question is neither  yes or no. The definition of a hero as shifted greatly throughout the history of french literature. Early work, during mediaval times, introduced the "knight in shinning armour". These heros were protrayed to be perfect and represented all the right values. For example: Yvain, le chavalier au lion.

Later came the 17th century with Racine and Corneille. This era introduced heros with flaws. Even thought most heros were seen to be the keeper of justice ( for example: Andromède, Racine), they still let weaknesses and flaws show.

Finally, during the 19th century was the rise of anti-heros. These characteres, althought they were the main protagosnists of the story did not always live up to expectations. As an example: in L'étranger, Camus writes in a hero riddled by anxiety, with a murderous past. These heors were also defined by being described as "complicated" and "misunderstood", making their reedeeming qualities harder to connect with.