Madanm, when I heard the sentence (Nou pral ale Jacmel demen maten avek ou." The speaker actually says sound-wise, "prale" for "pral ale". I know this is a spoken contraction, but is not this confususing to the listener? Instead, I pronounced it "pral ale". Also, if one were to say in spoken context, "prale ale", would it sound all right or sound funny? Mesi.

No, It would not sound funny.
When using the verb "ale" and the future marker "pral" we tend to do that.
Most of the time we do say "prale"; but once in a while we'd say "pral ale"

You will hear it most often when someone is referring to some "event" that is going to be happening soon.
Mwen pral ale talè.
I'm going to be going soon.
I'm going to be leaving soon.

as opposed to:

Mwen prale talè.
I'm leaving soon.

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