I've played every one of those options (DS Inq, LS Inq, DS Warrior, LS Warrior) until completing their stories on Korriban -DS Warrior until lvl40- and I was pretty satisfied with all of them. Each has their own benefits and all can make sense to a point, although some things you just MUST do despite being light-sided are a bit... awkward
Which one makes more sense as LS, though? I think Inquisitor wins this by a small margin. You can imagine your character as a force-sensitive slave who is just forced to face the trials unless he/she wants to die. And after that perhaps he/she wants to become more powerful to change the Empire from within and abolish slavery, or -as I did, since I'm a bit of a RPer- become stronger in the Dark Side (your alignment might be LS but you are still a Sith who uses the DS to fight) with a similar objective as Darth Plagueis: to learn to use the Force to cheat death and save everyone you love.
But LS Warrior can be pretty awesome too, especially because that's what makes more sense (still doable as DS though) if you want to befriend and romance Vette, who I find to be the best companion character in the game. And you can still get Baras on his nerves: that doesn't depend on alignment.