Have a look at my first post on this thread, which predates that export option in iPhoto, that pretty much deals with the issue with older versions. One of those options is free.
I'm just kind of irked by the idea that you should treat folders and files on your own computer as untouchable.
There are a couple of ways to look at this.
One: they're not at all untouchable. You have described perfectly how you might touch them. What we're saying is that touching them in that way may cause you dataloss, but if you want to do that, knock yourself out 😉. But know the risks you're running. Look at it this way: there's no reason you have to use the doors on your car. You can jump through the sunroof, but don't be surprised if you hurt yourself on the gearstick. 😉
Two: If you're the kind of person who really needs to visit with your files and folders for some reason, then run a referenced library. It makes for more work, adds zero extra capability and is likely to store up issues for the inexperienced user, but it's quite possible. For more about how, and the pitfalls:
https://discussions.apple.com/thread/3062728?tstart=0
Three: The bigger issue here is that you're going to have problems in the future. The files/folders metaphor is going away in computing now. Everything - even text editors - are becoming databases. The files are just dumb storage, the important part is the data - the actual photos. iPhoto is about the data, not the files. The Finder is about files.
These two user tips explain this is more detail:
https://discussions.apple.com/docs/DOC-4491
https://discussions.apple.com/docs/DOC-4921
Regards
TD