Fantastic report and pictures! I didn't have time to read everything in detail (will go back to do that), but skimmed through most of it. We were in the Southwest at the same time and also visited Havasu -- my take is quite a bit different than yours. I don't know if I would ever return. It was beautiful, but I was so disappointed by all the people, trash, disrespect of the land, etc. If we were ever to go back, we would stay in the lodge. The swimming holes couldn't be beat though.
And I have to say -- holy crap, you stopped at carhenge!! I grew up about 70 miles or so from there.
I see you mentioned going back to do the Subway in Zion. That's a definite. We did the Subway (along with Mystery, Keyhole, and Pine Creek) and it was one of the highlights of our trip.
Glad you had a great trip and thanks for sharing the pictures/report!