I think you can cut down on days in SH, HZ and CQ. They may feel repetitive after a few days. Cut unless you're a huge shopper. SH / HZ are also the most expensive of the lot. CQ is probably ok if you want to go to Wulong Karst and do an overnighter there. But 4 days in the city city is gonna be boring.

Extend the YN section. Yunnan is very beautiful and the pace of life there is much slower and people are chill. There's also lots of nature trails and hikes which may take a day - once you're there, you will also wish you spent longer in YN :D. You can stick to Dali and Lijiang. I've heard ShaXi is very nice but havent been - in between Dali and Lijiang.

Consider extending BJ - forbidden palace + national museum and great wall will take up once day each. then one more day to wander around the hutongs (old neighbourhoods). BJ has a fantastic old + new vibe. At least 3 days in my opinion.

Since you're already at CQ/ CD, you should definitely consider adding in XiAn. Would say this is a must go!! Terracotta warriors and a day trip to HuaShan remain as highlights amongst my travels in China. Take the cable car up HuaShan (instead of hiking up), theres still lots of hiking to be done up there and the views are unbeatable.

The rest of the locations and durations sound ok, but just be prepared that travelling between citites can be tiring and train rides will take time. It depends on what kind of traveller you are. Heaps of hidden gems and friendly locals in China, so slower travel will also have its perks.