If you are talking about changing your e-mail for your forum account, I don't see the problem there because I think you can just change your e-mail, you just need to type in your password so the effect can take place.
Now if you are talking about your in game account, I also don't see a problem there because I think you can just change your e-mail without notifying Neji, but you also type in your password for that new e-mail to take effect.
So either way I don't see how a hacker could change your account e-mail address without the password for the account. Correct me I am wrong on any of this information. You say, "I know to change my e-mail I need to ask neji but couldnt a hacker do the same thing," but I don't understand where you need to ask Neji to change your e-mail.