The best chance to change things for the better is probably in the post-revolution, as is usual for revolutions. While Haiti admittedly faced very serious external difficulties throughout the 19th century, it also had fantastically incompetent and very infighting-prone leadership, which just compounded those problems beyond all recourse. Had it been better led, I suspect it could have become a moderately prosperous nation, perhaps even with a flawed (rather than utterly laughable) democracy by the end of the century. It couldn't reach the financial heights it did before the revolution, but then that was built on slavery and perhaps wasn't desirable.
In particular, one point of departure I was struck with while reading about the revolution and the early 19th century in Haiti was how several of the early governments attempted to force freed slaves back onto plantations as if the revolution had never happened, in an attempt to gain hard currency through exporting the same agricultural products that Haiti had relied on before the revolution. The former slaves, meanwhile, wanted to carve up the plantations to establish small, individual farms, similar to Jefferson's vision of a nation of agricultural yeomen to the north, and were willing to fight to keep from going back onto plantations. This policy was therefore doomed, and attempts to enforce it only led to the country spilling blood and treasure fruitlessly on civil war rather than economically developing or preparing to defend itself against its many external enemies. If Haiti's leadership had decided to work with this social current instead of fruitlessly struggling against it, then the country could have been much strengthened early on. Perhaps this could have allowed them to resist the French reparations demands that caused so much trouble later.