1: Yes, you can set up sub-categories.
2: Yes, users can rate and comment. Ratings are currently included as a part of comments, i.e., if you can comment, you can rate.
3: You can set a category to dis/allow comments, and you can set whether a certain usergroup can upload to a certain category.
4. Users can upload to only one category at a time. If users want the same image in multiple categories, they would need to do another upload. Not sure what you mean by the second part of the question, but you can change category settings, and add or remove categories, when you want.
5: No, the vB attachment system is separate from PhotoPlog.
6: Check vbseo.com. Someone might have posted something for PhotoPlog.
Please feel free to try the online
demo and view the ACP
screenshots.