Hi there. Here is a pic of my bodyfloat at the lowest setting. As you see it's 4 1/2" from bottom of seat rail to tube insert. Would you have the proper seat height after adding a bodyfloat and your seat looks taller too.
That looks sweat. Did you ever see those plastic rubber type baseboards at your local lumber yard. You can use that as fenders under the rack and to where the rack two poles are attached to bike frame.