Rogues should get Principled and Aberrant. Hands down.
My first character was a principled elven rogue, and although there were times that I may have "fallen out" of alignment due to OOC laziness, I almost always played that way. Just because rogue skills -can- be used in a non-principled or aberrant way doesn't mean they can't be used otherwise.
A principled or aberrant rogue should be possible. I see nothing wrong with backstabbing, hamstringing, circle stabbing, or even stealing from inhumanly evil daemons, evil priests, necromancers, or other such folk whom you have issued a warning to, or picking locks to free imprisoned elven slaves from bondage, or picking Krychire's gates.
And considering the strong similarity between hellion and rogue skillsets, I can barely even believe that rogues cannot be aberrant. Come on people. If rogues could wear heavy armor, their skillset would be nearly identical, except for pick lock and maledictions. Circle stab/hamstring takes the place of hellfire, for damage.