2 weeks in China suggestion.

We are going to visit China next April. We will arrive to Shanghai. There are following places in our itinerary so far: Nanjing, Suzhou (Wuxi) area - gardens and canal towns, Hangzhou, Guilin/Yangshuo (return flight) for Li river and rice terraces and finally Shanghai. Is it possible to cover all places in 12 days? If not, what should we omit? Since Nanjing and Suzhou are on the same direction would be Hangzhou the place we could leave?