Don't worry about "farming" points - affection and LS/DS. Affection can be increased with gifts and the only thing that LS/DS affects while leveling is your ability to use relics. And I played a neutral character and did not miss relics for one second.
Up until this game, I felt that role-playing in an MMO was silly - that's what tabletop RPGs are for. This is the first MMO where I have actually figured out personalities for my characters. And those personalities do adapt over time but I do not allow LS/DS choices or affection gains or losses to determine what conversation choices I make.
In short I agree with Khevar when he said,
My recommendation to you is to pick the conversation choices you think is appropriate for your character. There are no real wrong answers that will affect your ability to do combat, or level your character, or affect your storyline.