Christian,
In determining what should be included in the ONPD, have you seen the JAlbum utility? It is fantastic, and I guess developed over a long time, as it is so comprehensive.
I posted a reply to one of the requests in here earlier today but not sure if you would see it as it's bedded down under a response hierarchy.
Check out the JAlbum. If you want to see one that I've done, it's only a few days old but will give you an idea of some of the concepts I think should be brought into here before I make Requests and stuff … just let me know and I'll give you a URL for a small album I'm just putting together :-)
Mark