I agree with Fidoric in the context of the Privateers game. If you're adding the stuff into an existing fantasy game, however, I'd be afraid of a slight power creep. Players tend to select disadvantages that don't actually hinder their character concepts, so balanced in theory doesn't always play out balanced practically. If I was doing SF into fantasy, I'd probably start by updating the fantasy races with MP dev and then slowly adding stuff in from there.
Of course it depends on your players too. If your players trend against powergaming, it shouldn't be a problem. Having an equal race with wider penalties and bonuses only really becomes and issue when player are working primarily for the numbers.