You're right it is placed in a spot that you would use for a focus point. I think the thing that pops out to me is how pointy/jagged it looks. To me the rest of the scape looks "soft" and then your focus is this "sharp" piece that for my tastes just doesn't go well. Don't let my opinion stop you from doing what you want though.
I'm not sure I would do the sand solely because it could be hard to keep everything out of it and holding the line. I've never tried putting a "stream" in a scape before though so I don't know.