Shadowdweller
Explorer
Seems like it at first. The thing is, a properly built fighter of equal level can often deal equal (or even greater) damage. Factor in the decreased accuracy and increased vulnerability of the rogue and you've got something pretty balanced. Also, while it may be easy to flank a target, you're often not going to be flanking in time for a full attack. So there's another bit of damage reduced. And many creatures, of course, are immune.Doesn't that make rogues incredibly powerful? A 10th-level rogue, with the right two-weapon feats, could be attacking up to five times a round, doing more than 30 points each time - 150 points a round.
(Also note: I think your listed damage is a probably a bit unrealistic as well. At 10th level, you've got 5d6 sneak attack damage...averaging 17.5 extra per attack. It's probably pretty simple to get a forehand attack to deal that 12.5 you're also assuming...though it's still going to be a pretty big investment. It's NOT so easy to get an off-hand attack to do the same).