[DNSB]

You can order and rename your library however you want. I used to do that before I started using calibre when I realized that I was spending more time curating my library and worrying about the directory structure than I was spending actually reading books.

However, the calibre library is not yours and there are pretty good reasons for most of the decisions involved in it's design/structure. As you have been told before, treat it as a black box and worry about the output files.

As for calibre forks? Last time I looked there were over 2000 of them. Most of the ones I've looked at were too many commits behind for them to be useful.