Hey! i'm a big fan of the game, and really enjoy the different languages the characters swear with.
I especially enjoy the french, as a French myself, but some of the uses of terms just don't work...
"J'en avoir plein le cul" is wrongly conjugate. You should say "J'en ai plein le cul". "avoir" is infinitive, so it can't be used in a conjugated sentence.
"Hélas", meaning "Sadly", with something changing. Simply saying "Hélas !", as simply saying "Sadly!" doesn't mean anything. If you want to use has-been traditionnal words, for the caricature, you may replace it with "Sacrebleu !" (nobody says sacrebleu in french, be reassured), or, for more modern terms, "Flûte !" which is a polite version of "Merde !" meaning "Damn it !"
little last thing, in french, the exclamation point is seperated to the rest of the sentence with a space. Exemple : "Bonjour !", not "Bonjour!"
These are the more common errors, but they are more charming that offensive. Seeing you, english-speaking people, saying French words is very cute, cause the English accent in French is consider cute, as for the French accent in English (from what i know).
Anyway, thanks for your game !