I'm not sure if it's valid as I'm not a meta-regular, but I can perhaps give some tips on how I'd like to see it improved as a potential answerer.
Your bullet list is not quite a check list for the things you want of the software, but a bulleted description of your context. I'd recommend rewriting it as a regular piece of proze, e.g.:
I want to bring order to the books on my Kindle. Kindle offers "collections", which are like folders/directories, but Collections are only available when you register, and I don't want to register the device.
From that context I can get 2 requirements for the replacement app you're looking for:
So, to summarize, I'm looking for software that:
- Must have: Doesn't require me to register my Kindle.
- Must have: Helps me orginize my books on my Kindle.
Then there's these three extra requirements:
- Must have: Runs on Windows preferably, but I'd try installing a Linux distro just for this if it is beginner-friendly to do so.
- Must have: Gratis.
- Nice to have: Compatible with using Calibre to transfer books to my device. (I'm happy to switch if there's a good reason.)
Mainly point 2 is a bit vague. You could help answerers by telling them what your detailed requirements would be, possibly ordered by priority or in MoSCoW fashion. Some things that come to mind:
What do you expect of the interface? Is the UX important or can you deal with a learning curve? Does it need to be aestathically pleasing?
Do you want a lightweight app or a power tool with many features (and if so: what power features would you like? mass-renames? regex-based searches? powerful drag-and-drop? a command-line tool to go along?).
Do you know any (features from) comparable apps (e.g. a music-library-app, or an old version of the app, or an app for other types of e-readers) that you like? Tell us about them.
What kind of "Order" are you looking to bring to your collection? Just a hierarchical folder-like structure? Or do you want tagging features? Special categorization features? Browse by author, isbn language or number, etc?
Again, I'm no meta-regular, so others may need to chip in, but I think you have a valid question at its core, but it wouldn't hurt to add some details.