I don't see a problem with doing Korriban first, as long as you do Nar Shadaa next as there's very little chance of gaining points either LS or DS on the Sith planet. To get Mira you could keep your character's alignment near enough neutral and should have enough time to go dark afterwards, especially if you leave Dantooine 'till later. This is all just a guess, though as Ive not tried it. I don't know anything about the Save editor, sorry.