Zhangjiajie visit in 2 full days (3 nights)

We have 3 nights/2 days in ZJJ in September. First, what is the temperature like for first week of September (typically)? Also, I want to visit the ZJJ Grand Canyon. Is it called something else on the internet? I cannot find much information on it or how to get there or price etc. If we are staying in a hotel in ZJJ town centre (near cable car to Tianmenshan), can we visit ZJJ Grand Canyon, Avatar Mountain, Hole in the Mountain, Glass Skybridge, all in 2 full days? How should we split the visit in 2 days? What other sights should I see? I am a photographer and I am looking for the unusual 'nature' scenic spots to photograph and sell to my friends here in Canada.