Medicine in may ways is not an exact science and you could find a paper written in any medical journal to support or refute your on particular take on a topic.
If the medical profession are at odds with each other it means that they just don't know the answer.
Men 21 units of alcohol per week and women 14 units per week has been the baseline depending upon, in my opinion, doubtful data.
I don't know the answer to alcohol tolerance in relation to longevity...Frank Sinatra and Dean Martin seemed to have done all right despite having alcohol running through their veins most of the time.
Alcoholism however is a massive problem and a drain on the NHS as diabetes, liver disease and the overstretched Casualty Depts struggle to survive and this is due to the uncontrolled drinking of the young.
This has to be controlled and if subterfuge is the answer, then I am all for it.
For the general population I would advice....drink for pleasure and not for effect.
My post has't helped at all.............;-)