If I go magic with a rogue I normally go rogue/wizard with my prime stat being Intelligence with Dexterity secondary. First 2 levels being rogue, then the next 3 levels being Wizard, then round it out being 5th level in each, then take levels in Assassin. In
PnP I hade a fairly nasty Fighter/Rogue/Necromancer that dual wielded sickles. When the campaign ended she had 4 levels of fighter 6 levels of Rogue and 6 levels of Necromancer.