Leveling an inquisitor now... class perk plus space perk, haven't had to touch a non-story mission, did the space dailies as a diversion when traveling back to the fleet or such, and already am over-leveled for Nar Shaddaa, where I am just starting the story line. No flash points, no pvp, no religiously grinding space, just when I feel like it.
Don't skip mob packs in your class instances, with some random killing along the way if needed while traveling, those do add up as well.