In my opinion, play how you want. I started my firt character as a pure light side jedi shadow and couldn't stand the na´vetÚ of accepting all things good. Sometimes characters deserve to have my lightsaber in their stomach. Similarly, I find it immensely interesting to simply answer in context now, regardless of class or alignment. My freshly rolled Jedi Sentinel got the Dark Jedi lightsaber for accepting Bengal morr's offer a d my SW is neutral because it is more interesting to question choices than to just spam one side's answer or the other.
So, it's your money and time, so play how you want!!
This is the crux of the matter - farming points (both LS/DS and companion affection) is BORING. Go with your gut, give conversation responses based on the personality you
want your character to have not what will generate the most points.