My trip to Beijing

Since I’ll be taking my family to Beijing shortly, I have yet to find out about these things….

1. Which part of the Great Wall is best to visit, between Badaling and Mutianyu ? I have heard and read that Badaling section has some tourist center, but very crowded, while the Mutianyu section is a lot less crowded and the scenery is more beautiful.
If I choose the Badaling one, I can also visit the Ming Tomb, but the Great Wall is crowded. If I choose Mutianyu, it seems less crowded. Can anyone please confirm?

Also, what I want to know is the Cable car at both sections of the wall are similar? Which part has a better cable car? And is the Ming tomb worh a visit?

2. I wanna see one show in Beijing, is there anything really good and recommended? Since I also will go to Hangzhou, and will see Hangzhou show there, if the show in Beijing is not that great, I’ll just skup and have walk around the city instead.

3.Does anyone know Exhibion hotel in Beijing? Is it good and close to shopping area?

4. most of all, how about of the forecast weather during sep 20-27.

Thanks all folks here for all your advice!