I did a trip, starting at the Power Plant campground near Atlanta, with a group of friends last year, going in the opposite direction you’re going.
1. One of the group climbed Glens Peak while the rest of us went down to Ardeth Lake to make camp (there’s an open-air pit toilet at Ardeth Lake at the southern end). He said it wasn’t a particularly hard climb, but he did lose his way and had to backtrack at one point on the route he took (since there is no trail that he could see). There’s actually a spot right before you start descending to Ardeth that could accomodate three tents, if I remember correctly.
2. I don’t remember the trail down Queen’s River as being all that narrow, I’d think you should easily find a camping spot along it.
3. Didn’t go up Nanny Creek to the lake, we went to Arrowhead Lake a bit north and on the other side. It was a very long, slow, steep climb to it though (well, followed by a steep descent to the lake after cresting the ridge). A very nice spot.
Also, there’s a very nice public outdoor hot spring near the Power Plant campground. Was wonderful to soak in it after our hike.
If you’re going to the trailhead through Mountain Home and then up Rt. 20, the road to Atlanta is a 20+ mile narrow dirt road, with nice kill-you-if-you-go-over cliffs, to get there. Very dusty road as well, so you’ll end up going quite slow. IOW, it’ll take longer than you might think to get there.
Atlanta is an interesting little town, up in the middle of nowhere. But there is a diner/bar where you can get a nice, tasty burger and a cold beer after your hike.
