4 days in SH (one of these is a day trip to Suzhou)
1 overnight in Hangzhou (maybe 1.5 days there, although you can spend more time there) - maybe a quick day trip to Yiwu to see the International Market and Hengdian Film City?
3-4 days split between Guangdong/Shenzhen.
That leaves you with 0-2 days. Maybe a stop in Xiamen.