Well if you look at the scenario you described, I don't believe the parent folder can be deleted while the child is pending deletion. And if the system crashes, I'd expect the file to be there (but haven't tested). So the path components do have to be kept around somewhere...
It's true that NT won't let you remove a directory if a child has a handle open. But I suspect you are getting the reasoning backwards. The directory is not empty as long as that delete pending file is there. Remove this ill-conceived implementation detail (and it is that) then this and other problems go away.
There is also an API that retrieves a filename from a handle. I don't think it guarantees the name be usable though.
It's easy to imagine a system that works the way I would have it, because it exists: Unix. You can unlink and keep descriptors open. NT is very close to being there too, except for these goofy quirks which are kind of artificial.
