Your third shot is quite amazing. Great ingenuity used as well. My wife and I had a short visit to Arches NP in early October, but not being familiar with the area, chose to hike to the Delicate Arch from the second parking area as the first was packed with vehicles. It was quite busy at the second and after a relatively short hike, we found we were quite a distance from the actual arch. The view was great, but I left my 70-200 in the car so the arch is quite small in al my photos.
When you took that photo, how many other people were there with you? At sunset while we were there, a large group was at the upper viewing area, with some people under the arch as well.