Can a Singapore to Beijing Trip be done in 4 Weeks?

Seems you're packing too many destinations in 4 weeks, by the 3rd or 4th week, you'll forget what you see in the 1st week. Concentrate on fewer cities that offer different attractions. I would skip Shenzhen, Xiamen, Nanjing, Kaifeng and Zhenzhou. Can you leave some of your stuffs with your friends, it's a big burden to carry so many lugguages in your transits.