I thought it would be beneficial to share my experiences on how I've spoken to GM's about multiboxing and why I have not received a message from one for almost 2 years.

The main rule of thumb is to make sure all your account match your personal info so there is no discrepancies if any decide to thumb through your various accounts.
Second is at one point you'll most likely receive a message from a GM either inquiring or testing to see if you are a bot. Instead of worrying about being on the ball and not wanting to miss their tell on a secondary character, you can go the pre-emptive route which is sending a ticket in letting them know you Multibox, and placing a request so that they can leave a note on your account that you do.

With this note, GM's will easily be able to identify your playstyle and ensures they do not accidentally act on something that is within their ToS. As well you shouldn't receive any tells from GM's in the future regarding this issue.

Again this is how I've taken the approach, and I'm sure it will make many of you sleep easier knowing your in good hands.