Impossible because:
But like always, there is a "time line" and a quest that start from early planet, so is near to impossible to rebot, the only solution are phases like in WoW, but we are really far from them.
Every character you play start the timeline from the begin. Example in WoW is pretty much different, beucase is the world that evolve and are not quest related to a "big main story".
You can't redesign the "new starting planet" and complete your character story without something wrong.
EDIT:
Main issue now is that if you go on these planets you go back in time... pretty orrible to think, but they are not the only ones