The problem with Revan's motive is that after Kotor, both games that came after retconned them so his story is disjointed because it kept changing.
In essence it's:
Kotor 1 motives: Conquer the Republic for power.
Kotor 2 motives: Conquer the Republic to make it stronger under his rule (and power).
Tor motives: Mind controlled to attacked the Republic by the Emperor and he then broke free to did it for himself.
It can work though. Seeing as Revan was always evil and the mandalorians wars only begun his slide, we can assume something gave him the final push. I mean don't you think its a bit strange that he ran off into the unknown regions then came back a sith lord bent of conquering the republic, without the TOR arc it makes no sense. Basically be combine KOTOR 2 motives and TOR motives. He found the Emperor, fell to the dark side, broke away from his control then went on a campaign to reforge the Republic so he could defeat the Emperor. The fact he had fell to the dark side and was corrupted by it, made him make this decision.
I think Kotor 2 was inferior to most Star Wars stories, for exactly the reason that it isn't good vs evil. Star Wars supposed to be a story about good and evil, by taking that away it basically turned the story into something else. Which wouldn't be a problem if this wasn't supposed to be a Star Wars story.
Sometimes its nice to have a change, things aren't always black and white. I agree it felt different from normal Star Wars, but I didn't resent it, I enjoyed its originality.
Nor do I think that Kreia's questioning the rules of Star Wars "worked" at all. All she did says follow you saying things that were either lies, wrong or insane. Nothing she said at all was wise or legitimately profound and I could pretty much safely ignore everything she told me. She was just annoying and useless. In fact I guess she was less than useless since she was the main villain and actively working against you. I came away from every final battle with her in my Kotor 2 playthroughs, happy I was finally rid of her insane ramblings. The fact that the game seemed to insist she was right made it all the more absurd and infuriating. The game seems to tell you she wins in the end because you gave her what she wanted but that makes no sense if I felt like I was ready to forget I ever met her.
Not going to argue with you here, seeing as its a point of view, but most people would disagree with you. GameSpy didn't make her the best character of the year for nothing. I think her dialogue was beautifully written and voiced, almost everyone who has played KOTOR 2 says that Kreia's questions about compassion made them stop and think. Of course some of the things she said are highly controversial and arguably wrong. But I think her main message was important. That Jedi and Sith should try not to be so dependant on the Force, and that if you have become so dependant on it that you can't live without it, you don't deserve to live. Its sad that you found her annoying and useless.
EDIT: Kreia is in fact, an anti-hero. She realises she has fallen to far and done to much to do any good in the galaxy. And that she can never become a Jedi or Sith. But she sees that you
can - she puts her faith in you, faith that you can be her last and greatest pupil who will defeat the threats of the galaxy (Sion and Nihilus) and make the galaxy 'see'.
But again, thats your opinion. But I will correct you on a few things. She wasn't the main villain, far far from it. Nihilus was the main villain, hence his blown up face being the cover of the box art where the villain always is in star wars posters. She wasn't working against you, her motives were to understand you and get you to understand yourself. She never wanted to kill you, that was a test. You or rather Meetra was proof of her beliefs, that you can live without the Force. Thats why she won in the end, because you realised what you were, and she believed you would help future Jedi yo try and be less dependant on the Force. Maybe her companions learned from Meetra, and maybe thats why the Order of the Prequels is not as arrogant and fanatic as the OR council.