Here's the question: Here's something you should consider: To master something, you should dedicate yourself to its practice. Sure you could walk towards the fine lines of the two sides, but you could never achieve the mastery of both. I could only imagine that you use dark and light powers at different points in time when needed just like switching lightsaber forms depending on the situation. This has been observed in KOTOR I/II and in The Jedi Knight (JK Outcast, etc.) series, and Force Unleashed. But with how you phrased your question and even quantified it, a mastery both sides would need commitment to both sides as well. When using dark powers, you would need to be fueled by your fear and anger as if you really meant it. And when you practice that continually to master it, then there is no more peace, but emotion. There is no serenity, there is passion. At this point, haven't you fallen to the dark side already? TLDR, You can use both powers is possible to use both the dark and the light at different times without letting the dark consume you, but you can only master the dark side only if you are already corrupted by it.

Advice from an Old Republic Jedi Master that is leaning toward the conservative side: The Order is built to protect the peace and the love of every being, something that I sense you value. As Jedi, we need to be unattached to tap into the Light Side of the Force in order to secure that objective. We always need to restrain our thoughts and feelings to ensure that they would not have to. It has been our burden and sacrifice, so that the ones we protect would be unencumbered. If we do not do this, then who will? I wish that these attachments does not affect us, those attuned to the force, this drastically. However, the risk is highly greater than the experience. With our potential, we could harm the very thing you wish to experience in a much grander scale. Advice from a more liberal Jedi or even someone not from the Order: Have you ever wondered that we(you) as Jedi could be too attached to the Code we(you) follow? Yeah, that code that says not to attach yourself, aren't we(you) too attached to it? Don't you ever ask if our minds are clouded by the Code, looking at it with bias as if it is infalliable? Isn't that an even more dangerous attachment compared to the commitment given to a lover? If you say that it is an exception, then shouldn't there be other exceptions as well?

1. A lot of Revan's hype was due to his charisma. Whenever he puts on that mask, you are not facing a Jedi or a Sith, but an idea. A symbol of unity in the Mandalorian Wars, a symbol of terror in . A lot of things about him has been exaggerated, since he is like, a symbol, a legend. I'd loved the book and the game because it puts him into a more human twist to him rather than legend. 2. You killed Revan, and he's now one with the force? Really? Did his cloak, armor, and mask got left behind after the purple flash of light just like Obi-Wan's robes did when he was struck down or ... http://starwars.wikia.com/wiki/Fold_space 3. I wouldn't even pretend to know what Revan is capable of at his prime, or at the foundry. I don't know which is potential, exaggeration, and capability because things are pretty blurred, and that's alright. So, I'll just enjoy the game take things at face value but still with a grain of salt, and worry less.