Yes. One of the best hikes in Arches is near the last campsites.

You can easily walk to Landscape Arch on the west side of the campground and a series of of arches that on the east side of the campground. You are not far from Fiery Furnace Hike, but you need to get a permit in advance or sign up for a ranger tour. You need to be limber since you have to do some bouldering. Park Avenue is another wonderful hike, but you need to drive to it. Do it before the crowds show up in the early morning.

Yes, the Devil's Garden Trailhead is only a short distance from the campground. My wife and I easily walked from our campsite to the trailhead. I highly recommend the trail.