Hey,
Thanks for the good ideas, especially wrapping with cheap rubber shelf liner material. I have a little trick for the open coupling ends. From Home Depot I bought four large (> 1" dia.) rubber table leg foot ends. These slip over the open couplings. I don't think that anything in the bag would damage the stainless steel but they are expensive items with exposed threads and protection costs little. For sure the sharp corners on the exposed couplings could scratch anything that bumps into them.
Tom