I think 18 should be the age for alcohol and firearms. You are an adult at age 18 when it comes to taxes, employment, court, and voting. But, for alcohol or firearms, you are a child. So, you get all the penalties, with none of the privileges/rights with the current laws. As far as driving, I think 16 is OK. I can understand people who want to raise the age, but the 16 and 17 year old kids are juniors and seniors in high school. They have more extracurricular activities, and are often employed for income. In some areas this isn't a problem since schools/work are close or mass transit systems are close. In my area, its at least a ten minute drive to anything, how is a 16/17 year old supposed to get to work or after school activities?
Also, I think a lot of the driving argument is not really age related, but experience related. Sure, when I was 16, I drove like an idiot a lot of the time, as did most of my friends. Most of us learned better driving practices because we had received our traffic tickets, been in accidents(minor), or just learned over time. I had a few friends that didn't get their licenses until 18 because they had no car, money for insurance, or parents wouldn't let them. They of course drove like idiots for the first year or two after they received their licenses until they gained experience. So whatever age is required for driving will be accompanied by higher accident rates for the first couple years.