The greatest indictment of the hard-driving slave system in the 18th-century British Caribbean was that the enslaved population never achieved natural population increase (except briefly in Barbados but only by 1810). Abolitionists seized on the failure of slave populations to thrive as a sign that slavery was immoral.
People down on their luck fleeing to the colonies on the first available ship is a mainstay of 19th century fiction. It was a convenient way for an author to either get rid of an unnecessary character, or to bring a surprise new person into the narrative mix with dramatic effect.
Historians of the British Empire have long recognized the hunger strike—famously embraced by suffragettes in Britain, and by nationalists in Ireland and India—as a transnational tactic of democratic, anti-colonial resistance.