Great shots of the trail. I have traveled that area extensively that past four years, and heading that way in late June/Early July with my youngest kid. Once you get to the bottom of Shafer Trail (also known as South Fork Road on some maps) you can travel White Rim Trail, the entire trail is about two days of traveling and there are places to sleep. However, a short drive will take you to Musselman Arch and you can walk over the arch, just don't slip.
Another one in the area, technically easy, is Salt Creek Trail inside arches NP, and you can even do a hike and see Tower arch:
and Eye of the Whale Arch:
Salt Creek Trail
And for some great desert travel, Horse Canyon Trail in the Needles Area, but beware, you need a pass, and Hummers can't make the entire trip, in fact, the Jeep just made it:
On Horse Canyon, you will find Paul Bunyon's Potty (I didn't name it):
(The photos of Tower arch and Eye of the Whale arch were taken at high noon, thus the colors are washed out due to the hot July sun.)