I'm currently tracing my ancestry back (it's SO exciting!) and I've discovered that Martinique and Guadeloupe are two of the MANY places it traces back to. ^_^ I just found out about "Kreyol Gwadloupeyen" and "Kreyol Matnik." As far as learning the languages goes, will learning "Kreyol Ayisyen" help with these other two Creoles OR should I pursue those languages separately like you told me about French? OR are the three languages so similar I don't have to learn these two other Creoles at all?

You might be able to get the gist of the conversation or hear a word or two (or a sentence or two) when listening to some "mostly French-based" Creole languages if you were to speak Haitian Creole fluently, but you do have to specifically learn that Creole language separately in order to benefit from it.

Kenbe la tande!

Haitian Creole ↔ English Reference, Look up Haitian Creole and English Words