OP; I am impressed with your ingenuity and fab skills. Good jigs also. Nice work. I often use EMT to mock up custom racks to show to customers for validation before going final with expensive chrome-molly tubing. I noted a few responses about the strength of the EMT or not. While I wouldn't normally go final with it...in the way you have used in and braced it, I would think it would be adequate for the job at hand. If you get the urge for touring around the world or down through third world countries, I would say you should upgrade to stronger stuff...
Press forth...and yes, please post more pix. Be sure to sand off the galvanized coating from the outside and inside of the tubes (go up about 6 inches on each tube) before welding, as that stuff is really bad for the lungs and not good for the weld quality either.
The rack has held up well through some pretty heavy duty use, so the EMT is more than up to the job.
As for welding galvanized, I am fully aware of the hazards, but thanks for the heads up anyway. Besides, my welding skills and my 110v hobby welder are not up to welding material that thin anyway, so no danger there.
I do have some plans for a few modifications when I can get the time. I'll post updates as I go.