Shan, I don't really understand what you mean about the raised Sumatra fault on 2 or 3 levels, but guessing at what you mean, it does not work this way: subduction zones don't work that way...the plate motions are not going to suddenly reverse themselves and make an earthquake going the other way. On the other hand, over the course of a century it is possible that some or even most of the vertical motions will reverse themselves....but not during a large earthquake....the flexing that occurs across a locked subduction zone cam cause the opposite vertical motions than the megathrust earthquake. This effect occurred after the 1964 Alaska earthquake. If you have an area that uplifts 5 or 10 m, but there are no high mountains in this area, then it is likely that it gradually subsides between earthquakes.
Chris