This seems like a good use for tags.
I actually have author tags.
fyi - maximum # of tags is 100,000
And I implemented internal tags and new field ($)
The screenshot is a receipt and I need to track the cost for separate items.
I use scripting on a Mac to insert the tags, and extract/merge the detail
>>simply ranking them, or subdividing into genres, or time periods, or some other subcategorization to then rank
Sorting is problematic. I have extracted data to a spreadsheet so I could sort it.
I also use saved searches to categorize by tag.
For example my task list uses tag:Important and tag:Urgent (Eisenhower Matrix)
>>I can select and edit some of those fields (date edited, author), but not all all (subject) - which is very surprising, since I wouldn't think you actually want to edit the "date edited" field (as a system property), but likely WOULD want to edit "subject".
I actually do edit the Subject Date field on my Mac using my process-inbox script
It seemed to be the logical place to store the subject date