1. What kind of alcohol do people take the most?

According to the WHO, 52% of Japanese drinks distilled alcohol, which is the most.
50% of the American drinks beer.

The rate differs between countries.

If you want to know further, please see the  World Health Organization report published in 2014.
http://www.who.int/substance_abuse/publications/global_alcohol_report/msb_gsr_2014_3.pdf

or the Wikipedia
http://en.wikipedia.org/wiki/List_of_countries_by_alcohol_consumption

2. Why do people smoke, even if they want to stop?
The are 10 reasons why people smoke


1.Peer pressure   Influence by the friends is one of the biggest reasons of smoking.

2.Social rewards   Smoking in groups give smokers feel acceptance, which makes them feel relieved.

3.Risk-taking behavior   The warnings like ''no smoking'' and ''not for minors'' makes teenagers that are not accepted in the society feel thrills. The feeling that they are breaking many laws makes them feel thrill.

4.Parential influence   Children who has a smoking parent tends to start smoking. They don't realize the risks of smoking.

5.Misinformation  Many myths are in the society, like light tobaccos are less harmful than heavy ones. Which is not true.
 
6.Genetic predisposition   There is a smoking gene that makes non smoking person want to feel like smoking.

7.Advertising   In the 1990s there were catchy advertisements that encourage people to start smoking. Advertisemets has a big influence. It can stop people from smoking if it discourages people to.

8.Self Medication   People suffering from some forms of mental illness, such as depression or anxiety disorders, may take up smoking because it can help mitigate some of their symptoms.

9.Media influences   The media has a large influence. If an actor in the movie smokes in one scene, the viewer may get an cool image towards tobacco.

10.Stress relief   Smoking tobacco refrains stresses, so many people gets addicted to it.

These are the 10 reasons of why people start smoking and it is also why people can't stop smoking.

Quoted from How stuff works .com
http://health.howstuffworks.com/wellness/smoking-cessation/10-reasons-people-start-smoking.htm#page=10