There's discussion of rumours, general discussion about what people think of certain units (i.e. not specific tactical discussion), and opinions about the rules/the game/the army. This is general discussion.
Rules questions saying does x do this? Or can I do y? don't, in my view, belong in general discussion. They belong in their own separate board. At the moment they're getting swallowed up by all the general discussion threads, so would, in my view, be better off in a separate board.
There really are not that many boards here. If you take out the campaign boards, both archived, and current, this is one of the smallest forums I visit (in terms of the number of boards), so if that's the primary concern with creating a new board, then I think that it's an unnecessary one.