Children go to grade 1 at the age of 7 and when they graduated from the primary school (grade 6), they should know at least 2500 characters, and the target made by the China Ministry of Education is as follows:
- grade 1~2: learn 1600 characters
- grade 3~6: learn 900 characters
about your 3rd question, I think it should be the time for Chinese lessons, there should be at least one Chinese lesson a day, and each lesson takes 40 minutes. you can calculate it.