However, it seems like a requirement that the entire directory/file structure has to be set fixed before burning starts.
Yes, exactly. This is true for all burning processes with NeroAPI since the filesystem with references to the filedata needs to be written first.
I also wasn't able to find sample code for the File System Content Interfaces -- did I miss it?
No, there is no documentation, yet. To use it do the following:
// set the volume name
// Get the root directory container,
// build it's content recursively
// add some files to the container
// add a directory to the container
FileSystemContent::IDirectoryContainer * pSubDirectory = pRoot->AddDirectory("New folder", -1);
// now you can use pSubDirectory to build the content of the sub directory
After you have build the filesystem tree, you can burn it with NeroBurn by using
the NERO_WRITE_FILE_SYSTEM_CONTENT structure.