Let me get this straight. You are angry that your husband works too much, you are angry that he is the only one capable of looking at a website (interesting, considering the amt of time you are spending on a website yourself), you are angry that the teacher is young, you are angry that the school hasn't taken your daughter's 504 seriously (has absolutely nothing to do with the current issues but perhaps thrown in to build up the case you don't have?), you are angry that your snowflake isn't challenged enough in school because she's so much smarter than the other students, and you're angry that the teacher doesn't print on all assignments that a grade is given. IMO, it's a no brainer for most intelligent people to know that assignment=grade.
And because of all this, the teacher is now subjected to an angry hateful email telling her how she is not doing her job?
Perhaps you should logoff and go check to see if your daughter needs help with her homework so she is not penalized again for you and your husband dropping the ball.
ETA: Forgot one! Also angry about not being able to pay for private school which would solve all the world's problems, evidently. Oh, and MIL is frustrated, too, which somehow supports the arguments.