just wanted to update this thread. After all the toiling over this and figuring out what to do I ordered the BAL hidden spare tire mount.
That's kind of how I do things from time to time.....put in a bunch of time and effort on something then change my mind completely.
I actually bought the tubing, cut it to length, clamped it to the bumper, and drug the welder out to the camper. I'm laying on my back looking at it and I just kept thinking "How much is having this back here going to bother me the next 10 years?" I decided that I would never feel completely comfortable having that spare on the bumper. I would worry about welds failing or if I had enough bracing ect ect for the next 10 years. Found the BAL mount for $86 shipped and decided the piece of mind was worth probably twice that. Just seemed like the right thing to do.