1, there are quite a few people. Suggest going in the morning. There are generally no seats in the afternoon. It is open from 7 am to 8 pm. Suggest going early at 7 or 8 o'clock.
You don't need a card. There is a reading room in it. You can go in and read magazines without a card.
3, the environment is very good and quiet, both on the first floor and the second floor.
There is also a tea room in the museum with hot water supply. Many people bring their own instant noodles at noon.
Lunch suggestion: Lunch service can also be provided on the third and fourth floors. Various noodles and student meals are available for you to choose from. There is a coffee shop on the third or fourth floor. But if you go alone, you should bring your own lunch at noon. There are convenience stores and KFC in the nearby subway station. I usually buy more in it, half breakfast and half lunch.
I hope I can help you! !