I liked this side quest. It's generally balanced and the dialogue is interesting.
A few comments.
I'm assuming that this quest will be available from the start of the game. So, Duvalier might have low stats at this point.
So, having aptitude 16 or more might be quite rare. Furthermore, having aptitude above 21 would be unseen (unless if playing a New Game +).
Compare with the stats needed for the Tikki side quest.
These chickens are not that strong, which is a good thing. However, the psy form is disproportionate. At least, having a "flee" square in the battlefield would be advisable.
The Egg Shot would be more interesting if it was a counter (hitting range 1-2).
Regen of 20HP per turn is a lot!
Now, if this side quest should be played later in the game, getting the key is too easy. And the chicken normal form is also too easy.