I really need to programmatically modify FLA file. I understand that they are some kind of ZIP archive, but 7-zip cannot open them at all, and although WinRAR and Windows Explorer will open the archives, it will report that the archive is corrupt if you try to extract or update some files. This makes it very difficult for me to edit existing FLA files.
The XFL format is not a solution.
I would be happy to have a way to modify one of the XML files in the FLA file, for example to perform batch modification of a referenced SWC component's path (since the file name was updated, and it's referenced by hundreds of FLA source documents).