I could have written this entry myself, so much I agree with it, and I find myself in a similar situation. Plus for some strange reason when I go to the edit page only some categories appear, which means that if I only open to edit an entry, and close it back I generally loose some half of the categories that I used. Hmm. But I really love categories as tags, so I am very interested in your project. Plus I was curious to know if you had the same problem with your wordpress: not all categories appearing in the edit page (but all appearing in the manage category page),