[Impulsiveness] can be a good thing, every once in a while...

Definitely true, as the case with Lee. The way he flew down that conveyor tunnel had a bit of impulsiveness involved. However, when someone is relentlessly impulsive, that could be a problem, and it gets old after awhile.

It constantly feel like the writers are winking at us, telling us, "See, we get it. Heroes can be flawed. So, we'll give you Kara, who is frakked up, emotionally unstable, but doesn't she kick ass."... I prefer Lee...

I see Lee as a well-rounded protagonist. Like the best of us, he has faults and makes mistakes. But even at his worst, I was able to get into his head, "see" and understand his thinking process. As such, I get to see him get past his funk, (at least attempting to) overcome his mistakes. His character matured and grew up right in front of my eyes.

With Kara however, I wasn't able to look into her head and understand her. I feel the writers are too busy at having her do the next "unexpected" thing that they don't bother to explain the "whys". A fellow bsg fan described her to me as being consistently inconsistent, which I think fits her to a tee. Nothing she did in the show, however unconventional or unethical, were ever wrong in the end. Even when she "killed" herself, she came back an Angel. So there wasn't a need for her character to change, to mature; and she never did (so far).

so she decided not to give their couple a chance, and broke things off before it could start.

But it had already started. When two people profess love for each other, in that intimate manner, whether or not alcohol was involved, things had already started, big time.

The point is, I never got her doubts and fears from watching that episode (and the ones that followed). As far as I'm concerned, your theory (a very plausible one) is a fanon instead of canon to excuse what she did.

You see, based on what I saw, I feel she loves Lee. However, she also loves Anders. She doesn't know which men she loves more, but she sensed Anders is easier to..."control" (for lack of a better word), and more prone to turn a blind eye to what she does. So when Lee suggested her to break things off with Anders in the morning, she panicked and ran off to *marry* him instead...

all she said was that marriage was sacred (since she believes in the gods, taking a vow before them counts a lot). But then, why feel free to cheat on her husband?

Actually, I think she gets off on the illicitness of the affair with this beautiful man. Kara had always frowned at convention and ethics, so the illicitness shouldn't bother her. That way, she also didn't have to commit to Lee. It's a win-win situation for her if only Lee had cooperated...

But again, we've seen no indication that the Centurions were anything but machines, with very little thought-processes.

Hmmm, that remains to be seen I guess. From the way the Centurions were introduced in this series, that certainly is true. With the missing "reasoning-chip", I don't see how they can be self-aware. Unless it turns out these Centurions were "dumbed down" after the first Cylon War.

I think it was said in the mini that after the first war, they retreated to a planet outside Colonial space, and were never seen since then.

I could be wrong, but I've always thought they retreated to the SPACE outside the colonial space, not a planet. I've pictured these cylons "lived" in space somewhere with no place to really call home. Hence they came back -- "humanity's children came home" to reclaim the planets.

I got the feeling that the first war happened because the Cylons wanted to be 'free' and escape the Colonies. The religion happened between the first and second wars, and the second war happened because the Cylons had decided that the humans didn't deserve to live (but then, why have farms and try to understand how humans reproduce?)

Very plausible! :)