2011 on 7 mile rim
I would venture that 7 mile is the most challenging trail on your list there. There are some good size steps near the beginning of the trail that might prove too close to your sills, but I'm not sure. Even though we just pre-ran a bunch of the trails including 7 mile Rim, after Easter Jeep Safari, the trails can change quite a bit! Some places are dug out more, some places are stacked high with rocks...
It would be tough to catch up to a group on an easier trail that you haven't already run. E-hill would technically have room for you, but they'll be hours ahead of you by the time you turn around on 7 mile rim. Frankly, I think the steps on e-hill are about the same size as the ones on 7 mile rim too.
Maybe you can work up a backup plan with someone in camp to go do some exploring together if 7 mile is a bit too big for your tastes? There are many trails in the same area as 7 mile rim that would prove fun with your 2011. 3D Jeep Trail is a soft surface roller coaster for example. If you have a ham radio and a map, you could keep tabs on the 7 mile rim crew and catch back up to them after they pass the Wipeout Hill obstacle.
If you choose to go exploring the area by yourself, be very careful. No one will know you are stuck, broken down, hurt, or lost out there!
Another bail out option would be to go explore the dirt roads, hiking and photographic opportunities in nearby Arches National Park.