[szobel]

I too would love a single staff, but for me it seems like it would be most useful if it were a "shape" that I could extend to whatever length I need.  No need for clefs, etc.. I would just write in that sort of information, plus, if you're just adding alternate lines, or arrangement ideas to a lead sheet or existing part, the clef, key, and time signature are implied.  Right now I make 5 lines with the shape tool, but it is a little cumbersome and hard to make them even and straight.