I do the same thing, but my tongue normally goes back another 18 inches, just before the axle, and it is triangulated with 2x2. I do not run a center back bone down the trailer, due to water tanks, and the limits it puts on the tank size, or adding additional plumbing. I have started using welded D clamps for recovery. I also put them on the main rail sides.
I had box type trailer that I had the receiver hitch out the back, it seemed to me it was more trouble than it was worth. I also had a spare tire hanging off the back, and hated it, as it was a swing out and took so much room when camping. I now try to keep the back of the trailer as clean as possible. Although for highway travel or fire road, having one would give me a place to put the bicycles. Currently I carry mine on the side, just loosen the ahead set and twist the bars. Pros and cons to anything. Do what you think will make you the happiest, and if it does not work, you can always build another one, heck its only time and money!!!!