Hi Wilson - I had the same thoughts you do about the "heavy controlled" drinker, "walking the line", etc. and I also understand how it becomes a like a challenge to be able to drink and hold it together at the same time.
If you're like me, it will get increasingly harder. The progression of my alcoholism was very slow (it took 20 years to go from 6 beers/half bottle of wine a night to 10 beers/bottle of wine a night, with 6-8 years of sobriety mixed in). I wasn't drinking everyday either - just went on 2-3 day binges and then took it easy for a couple days. I worked very hard at my drinking because I didn't want to quit. Infact, I wasn't sure I could quit even if I wanted to.
I used to wonder if I was really an alcoholic (yet). Then I looked at the newer models of alcoholism, which show a continuum rather than a distinct category, and found that I was definitely at least a stage 2. The other thing that helped me was when I saw that the acceptable level of alcohol intake is 1-2 drinks per day for women, and 3 for men. I couldn't deny that I'd exceeded that every day I drank. So even if I was holding it together in some ways, I was slowly destroying my body.
I applaud you for your 4 days sober! Once you get a week or two, you may find (like I did) that your life while drinking wasn't quite as functional as you thought.