1) I guess I drink alcohol about once a week on average. Most weeks its a bottle of wine share with my wife (about 2/3rds for me an 1/3 for).
Some week I don't drink and some weeks I perhaps get drunk on about 10-12 units of alcohol. (that amount of beer, about 2 bottles of wine, 1/3 bottle of spirits or a mix of that.
2) I've had a couple of times when I had to much. I think I've had perhaps 3 periods of lost memory, and about 10-15 episodes where I got sick. Most of these episodes happened when I was in high school, or at University.
I've never been intervened on account of alcohol, well once when we were a bunch of people drinking and talking, and I mockingly pretended to throw a plastic bottle at a guy, the bottle of course slipped and hit the wall 2 cm from his head. My girlfriend at the time yelled at me for being to drunk, and I still get embarrassed when I think about it.
3) Everything in moderation, the saying goes, and I think this applies here.
Alcohol consumption, like many other activities carry within the possibility for becoming problems.
The answer I think is just that f you experience that the rest of your life suffers under one type of activity, then you have a problem.