I remember hearing those voices inside before I got married. My experience was like yours--and your description of your fiancee matches my AH to a tee. My warning alarm was flashing all over the place, but like you, I figured, it's not THAT bad. I love the guy. He's great when he's not drinking. I can deal with it. You will see this same line of reasoning consistently with people who are in the same boat as this. Lots of them are here on this forum--others have had more history and have learned that the drinking part quickly overtakes the great part of his personality, and that it's very difficult to deal with, and that even though you love the guy, you have to work very hard to not hate him after a while, and it's just as hard to learn to detach with love.
Now, I'm not about to say I regret my decision per se, because that would be like regretting the whole past 34 years and my four wonderful children.
But, if my desire and intention at that time was not to marry an alcoholic (which it was, clearly, based on my mother's own experience), I did the wrong thing. My "wonderful when sober" AH has put alcohol above everything in our marriage, except for 5 short years out of 34 that he was sober. He's put it above truth and integrity, his relationship with me, our financial stability, and his business.
I went with him to Florida last week to his dear departed mother's best friend's 65th wedding anniversary. This wonderful woman, age 87, came to talk to us at our table and do you know what she said to him? Not, nice to see you. Not, you look great. She said, "J.., your mother talked to me before she died [last summer]. She told me how worried she is that you drink too much. She said 'he has to stop or he's going to die early like his father. I'm worried about him and his beautiful wife.'"
He had already had a few drinks, and he said, "Geez, I didn't know I was coming here for an intervention." Then he said, "Can I sing a wee song now?" She said, "No, you are not singing a song. Listen to what I'm saying. Love yourself. Stop drinking. Take care of your wife."
To which he said, "But I love to drink."
Play that scenario in your head and ask yourself if you want to be there in my place in 34 years.