As long as your coach is in compliance with the law where it is registered you are legal in all other states. The same for driver's licenses.
We recently changed our registration from NY to TX and were required to take the written and driving tests for Class B non commercial driver's license. Part of the test was a walk around of lighting. The examiner did not put us through the air brake test as detailed in the handbook and the back up test was a straight line of about 50 feet on a road with no traffic.
