Can you take or grant rights in Netflix to the other users / accounts with whom you share the account?

I just want an account with admin rights, the others should just log in but not be allowed to do anything on other profiles. I don't find the function. Are there any?

Unfortunately not no, you can only set it up to be a children's account to block certain series / films

A user always adjusts the profile pictures and names of the others. For fun. Can't you do anything about it?

No, unfortunately your hands are tied, you can't change anything except change your password so that this person loses access. : /