I really don't think that variant pages are necessary. You can add those pictures to each character gallery where they belong. But you're free to create any article you want. To add a category just go to the bottom of the article.
And for your second question I don't understand. Add borders to what...?
When you are editing the article you can see |- bgcolor="#eeeeee" ... if you want a different color you go to some HTML code color website to select a new color and then go back to editing and add that new color.