Personal opinion:

1. The internship salary is currently 1,311 yuan, which is almost the same. The company is not too high-end and should not exceed 2,111 yuan;

2. It is a normal practice to take a diploma to become a full member;

3. It's good news to make up the difference after becoming a full member.

4. If you get a diploma, you will be dismissed. Generally speaking, you won't. It costs far more than you can see to train an intern to become a success. If you are good enough, please trust the company.