Some minor grievances.

1. When the same image is repeated several times in the webpage this plugin downloads&adds the image each time as a different image (saves it under a different name). It would be more elegant&efficient if it only downloaded the same image once!

2. Empty style sheets should be deleted!

3. Also you should change the way the files are renamed inside the epub. It's best if you keep these names independent from the source files. Something like,
(a constant for given file type + index value).extension
would look better.

Thanks for the amazing plugin. I have plenty of uses with it.