My experience with drink is not that it makes one more creative, but rather that it silences the inner editor (as a facet of the "removes inhibitions") and relaxes anxieties. Having a half-bottle of wine makes me absolutely no more creative than I was before I had it - but if I've GOT a head full of ideas and a drive but am having difficulties with "agh, god, it's all awful!", then that half-bottle of wine results in a lot more words actually making it out of my fingers.

As to how they think they can drive, a) people who drink more often get practice in faking sobriety and sometimes manage to fake themselves out, or b) they were that stupid when they were sober, too.