2. Of course, China people can take the Chinese exam, but you also need to have a certain English foundation. After all, the questions are all in English.
It's hard to decide, but it depends on your interest, which is better. Biology and chemistry are generally relatively simple. You can ask the domestic tutor first. You can do some slightly more difficult topics and buy the original English sat II book to read. I may not understand some words, but the topic is not much more difficult than China.
4. this. . . I don't know. . Almost all are AP-level. . . That is, students here will take pre-university courses. A degree is also equivalent to a university. You can buy a book to do it. There will be detailed review exercises ahead. Later practice exams will also have detailed answers.
I suggest you choose Chinese, math, chemistry, biology or physics. These don't need much English, as long as you are often exposed to familiar questions, you will definitely get high marks!
Come on!