Just FYI, until late 80-s, the earliest age for woman to be legally married in my country is 12 yo. This rule applied to accomodate the lifestyle of people living in the village, where level of education and knowledge of child/mother health care were still low. The age limitation then increase to 18 yo, which mostly aimed to lower death rate of mother and her baby due to early birth/pregnancy.
As for drinking alcohol, if I'm not mistaken, there's a verse in Bible that said (more or less) " it is easier for camel to enter needle hole, than for rich man to enter kingdom of heaven". However, I don't think Christianity prohibits its followers to be rich. It's ok to eat; but if you eat excessively, then it'd lead to problems. So same thing apply with drinking alcohol I guess.