Also, him fighting the Republic to "prepare it" is really unrealistic if you think about it. Anyone who knows war knows that war always weakens the nations involved. By doing what he did, he didn't prepare the Galaxy for the True Sith, he only weakened it. Maybe he's not as brilliant a strategist as Kreia thought.
Your forgetting something very important - Revan had the -Star Forge- to strengthen it back up duh - he just needed everyone to follow him and that was the only way to accomplish it. (the war)