Actually, I'd say what you cite as advantages are actually disadvantages. There's a reason that Haiti has preferred to hop into the British, American, and even German spheres of influence over the past 200 years over associating with France. The "cultural familiarity" the Haitians had with the French was an experience of them being brutal slavemasters. That's why during the 1804 massacre, the only whites spared to my knowledge were non-French European nationals, which summed up to about 100-200 Germans and Poles. The British had much better chances of conquering Haiti because unlike the French, they weren't as universally hated at first. In fact, the white population of Haiti (in 1793, pre massacre) even welcomed the British in, viewing them as preferable to the French. Of course, in the OTL invasion of Haiti, the British started re-instituting slavery in their occupied regions, causing them to become universally hated and driven out, but that doesn't have to be the case ATL. Conversely, even when the French abolished slavery and armed former slaves to drive off the British, they still weren't really trusted by the populace. And post-independence, the Kingdom of Haiti under Henri-Christophe recruited British advisors and tried to drift into the British sphere, with mixed results. It's a complex subject, which I'm paraphrasing a bit for the moment, but I did just want to get the point across that the historical French presence in Haiti mostly serves to their detriment.
As for language, the vast majority of Haitians would have spoken Kreyol at the time, and the variety spoken then may have been even less mutually comprehensible with French than it is today (which is to say, almost not at all).