I agree with you about Force lightning, though. Especially, I think it shouldn't be a combat ability. It is a way to kill people painfully, because you want to see them suffer. (The Emperor could have snapped Luke's neck, if he wanted him to die. But he wanted him to suffer.)
I especially don't like the lightning-insta-kills the Inquisitor in this game does in cutscenes.
not necessarily, the force user can vary the intensity of the lightning, this much is clear - for e.g 'dooku/sidious can make it powerful enough to throw you across the room while burning, or makeit painful and long, or the intensity high enough to kill, like when Mace reflects the lightning back at Sidious, he is doing something we have not been given an explanation for, but that was damaging Sidious quickly.
Furhtmore, lightning can be conducted remmber, lightning rods etc, why can't jedi trained in this knowledge know how to do so either with thier hands (Yoda) or with a lightsaber?
i do agree it shouldn't be something easily done , Obi Wan almsot too casually mangaes to attract the lightning of Dooku in episode 3...however i am more inclined to suspect, this is a force technique and lightsaber modificaiton working in tandem that YOda tuaght them.
As i mentioned earlier, the jedi at that time had almost no working knowledge of the Sith or the dark side, , but YOda having been alive in the last confrontation would know extensively especially since he was one of the strongest jedi about.
This epxplains how force ligthning can be used as an ability in-game. and yes your inquistor would be able to insta kill with a lightning zap if it was hiis intention. as for it not being portrayed aspowerful enough in-game because they didnt make it an instant kill ability, remember being shot by a laser or a bullet/laser is not an instant kill in the game, tho it is irl, and in the movies, yosimilarly - conversations always display those actions could view force lightening