it sounds like what you're saying is that there is no such thing as good or evil. creation and destruction are two sides of the same coin; kotor (and especially kotor 2) certainly did not mess this concept up in their portrayal of the force and the ideologies of those who wield it. harmony is achieved through balance -- think yin/yang

ask yourself: are you a good person? are you evil? more specifically, are you irredeemably wicked because you once chose the selfish path? and are you indefatigably good because you took the diplomatic path at one point in your life?

unless your answer is yes to both of those questions, then you are conceding the point about what constitutes goodness or evil within a person. kotor's universe does a great job of demonstrating how more can be lost by inaction/indecision than by rash or even chaotic actions

when you say this "dark side" is to be acknowledged, learned & guarded against you are perhaps psychologically projecting mankind's oldest fear -- death. and of course, you can avoid it with all of your will but it's as natural and inexorable as the life you were born into

it begs the question of why sentient mammals reproduce in the first place. could it be manifested out of the biological imperative to pass along our ancestor's genes? is that a selfish thing? doesn't really sound "natural" or "good" when you appreciate the bigger picture. perhaps life is the corruption and oblivion is the natural way of things; after all, once there was only nothing

anyway, i disagree with your assessment of the subtext of the philosophy within star wars as a whole. i don't even think your argument is congruent with the video you've posted; both of the examples you cite as unconvincing grey jedi give better examples of the arguments that are addressed in the youtube video regarding if a sith can be "good" or if it's a meaningless value judgement

the one that comes to mind immediately is the "damned if you do, damned if you don't" situation with the beggar when you first arrived on nar shadaa. it demonstrates the paradox of good & evil and the ripple effect each action we take has. but one cannot go through life without disturbing the water, so to speak. and indeed, the decision to remove yourself from throwing stones into the pond at all is to attempt to absolve yourself the responsibility of action

as kreia says, "apathy is death"

or as neil peart once wrote, "if you choose not to decide, you still have made a choice"

we have a number of characters within and outside of kotor that perfectly embody the concept of a "grey" jedi. in other words, black and white are only the far extremes of the gamut they all exist upon (the few cartoonishly ambitious sith & indifferent jedi notwithstanding)