Assuming the retagging proposal regarding {floats}, {tables} and {figures} is implemented, questions about the figure
environment should be tagged with floats. This begs the question what (if any) area of application remains for the figures tag.
The graphics-related tag with the most questions attached to it is graphics. Its wiki entry says: "Use the {graphics} tag for general questions regarding inclusion of graphical material in your document, usually from an external file. If you'd like to discuss vector graphics created programmatically inside a TeX document, use the general {diagrams} tag, or preferably the tag for the vector graphics package you use (e.g. {tikz-pgf} or {pstricks})."
graphics, tikz-pdf and pstricks seem like good choices to me. On the other hand, I noticed that while the diagrams tag features 27 questions at the moment, only one of them is also tagged with graphics. I take that as a hint that diagrams is rather used as a synonym for graphics and could be merged with it.
Then there's the picture tag (14 questions). There's figures -- 86 questions at the moment, but prone to twindle because of the upcoming retaggings to floats. And there may be even more graphics-related tags I've overlooked.
Please provide input as to which graphics-related tags you view as essential, and which as dispensible.