The administration page for your Kindle content (called FIONA) is what inspired me to start working on something better. So far I have assembled the bits and pieces on how the bloody thing works, and used that info to create a
minimal python library along with a minimal sample program that uses it.
Basically it is just using the underlying server API that the userscript/bookmarklet is indirectly using through the extremely badly written Javascript code from Amazon. In that regard it can serve as a basis for something written for a browser. As in something larger than the little bookmarklet. Perhaps a plugin for Chrome that can manage content? I was thinking of filtering on title, mass deletes, and such. Would that be interesting?