How important is Spanish Cedar?

I think your setup is also okay. The only thing is I don't think most cigar boxes, at least the cheaper ones covered in paper panels with illustrations, are made of cedar at all. I don't know what wood they're made of, but I would still keep it in there. Cedar has a slightly sweet, kind of fruity aroma. It might be hard to smell when they're dried out (like in that stack of cigar boxes in the corner of your B&M), but is very noticable, almost "stinky" when wet or moist. If you want to add that "cedaryness" either get a bunch of the sheets that come in each box, or sometimes varnished boxes for high end cigars are lined with it, but not always.