On this page for example:
The categories show an icon in front of them. These are in the html apparently. Can this be put into the CSS via pseudo-elements to make theming easier? A lot of people may not want to use those icons or may not want icons at all.
Ditto for the phrase "posted in" which personally I find redundant and don't really want to see many times on a page. I think that should be optional for people and is more of a display thing and can be inserted via pseudo element for whoever wants it. Same goes for "replied" and so on. These phrases are repetitive and may not be necessary for many themes.
Again this will just make theming a lot easier if stuff like this is in the CSS.
A class on the category could also make it possible to do color-coding and so on...