This was my advice to a guy that has people in school only call him by his first name. What do you think? Is the whole calling foreigners by their first name thing disrespectful?
Actually, I think it is disrespectful. Let me guess, 9 times out of ten they don't bother to affix an honorative to your name, such as さん or 先生. They want to set you apart because you are foreign.
The compromise I reached was to have everyone call me Mr. B. I explained this is how we handle teacher's names in America. Therefore, it's easy for them and I feel like I am getting some respect.
Now, it's gonna be an uphill battle, but here is my plan for you. Start an English radio show on the annoucements at your school, and make sure the teachers room can hear it too. Do the show during lunch.
One of the first things you will talk about is how to properly address a teacher in an American school. Then say, "だから、今から、君たちは僕にミスタXとよんでくれませんか？" and follow up with how it is rude to call a teacher by their first name, even for other teachers.
Also introduce yourself on the show each time as "Mr. X". Correct students and teachers every time. Soon, with luck, they may learn. But don't count on it for your current students.
EDIT: sorry I had to hide the comments; I am starting to get paranoid about my last name being online!