Fidelity

First, why the cynicism? Have you been hurt previously by love?

If your truly in love w/ this woman do you not desire to spend most of your time with her? To spend most of your energy around making her happy, to see a smile that will warm your heat.
Yes, you may risk hurting her, but then again, even if you were monogamous you still may hurt each other. The world is full of uncertainties and you shouldn't really spend time worrying about them, just do what YOU feel is right, and being the intelligent logical and good person (presumably) you are, it will be the right decision whether people are hurt or not. As long as your intentions are good I believe things happen for the best in the long run.
Remember though that men and women are very different. Understanding women to the best of your ability could never ever be a bad thing. The more you know, or think you know even, the better off you are. Knowledge is power, in ever aspect, without a doubt.

Understanding yourself... I'm not really sure. I can only speak from personal experience, you know? The way I see it is, if your perceptive, smart, and have a desire for knowledge you will at a point question life, your impact on it, spirituality, the past and present, many things that have relation to existence. Once you question these things and find out where you stand, through research and personal exploration, you should have some sort of bearing on where you want to head in life and what you want to stand for. This won't be easy, and it may take a long time, but you will become the best person you can for it. You can pursue business ventures, love, excitement, adventures, anything you wish with the right know how and desire.