Kierkegaard went to the theater a lot, and mentioned Bournonville several times in his writing. He said that one leap of Bournonville's (as a dancer, as Mephistopheles in his "Faust") made him understand the demonic, namely, it is the sudden. That's a paraphrase from memory, and from his diaries. I never could find any reference to "La Sylphide," which is very odd, as it would seem so relevant to Kierkegaard's own life.
I don't know if the Agnes and the Merman story influenced Bournonville, nor the dates of the other writings, and don't have time to check it tonight. "Napoli" is 1842, and was written in 1841. He was directly inspired by his trip to Naples and the blue Grotto, but that doesn't mean that other stories may have been worked in.
On the second act choreography, I've read and was told tthat Bournonville's act was not badly chhoreographed, just a lot of dancing for the audience of that time, especially the men, who weren't as enamored by a stage full of women as were their French contemporaries. The act got chopped, down to the mime, a pas de deux and the transformation scenes by Lander; afterwards, others have tried to choreograph something "after Bournonville." I can't comment on the present production, of course, as I haven't seen it. I hope someone else will.




