Thoughts on the 21 drinking age

Apparently there is some debate as to whether to lower the drinking age back to 18 (1984, the year I was born, was the year they moved it nationally to 21.) Since I am a teacher, and in particular a teacher of 10-12 graders, I have some thoughts about this proposed change.
(Note: I did not start drinking until age 20. I'm not sure what made me hold off till then as I didn't see any moral issue with drinking.)
1. An argument I have heard: In Europe the drinking age is younger so people learn earlier how to handle their liquor- is that really it or is it the culture that more so pushes people to just sit and have a drink with dinner as opposed to the US culture that pushes people to get wasted?
2. Any crime that punishes enormous quantities of people should be questioned- if that many people are getting punished for underage drinking, should it be a law or should we look at other alternatives if we don't want young people drinking? (More importantly do we want to look at alternatives to teaching people to drink responsibility?)
3. I didn't drink in high school largely because of the group of people I hung out with. We "didn't need to" I guess? I think a big part of it though was that it wasn't legal and we weren't the types to break the law since by the time we all turned 21 nearly all of us had been drinking already.
4. I do worry about the 18 thing. I was 18 before my prom and before my graduation. Lots of people drink for those events but I guess I'm most worried about people driving with those events. By the time you get into college most people live within walking distance so it's a lot easier for people to drink and not drive. High school, most of my friends were a 15 minute drive away. That has to be my biggest problem with lowering the age I think.
5. I don't like the fact that the age to get into bars is different from the drinking age. That's dumb. That being said, I also don't like that people have to wait until they're 19 to get into bars and I don't like the colleges that don't let you into the bars until you're 21. It would be great if people got into college and could go to the bars AND drink if they would like. I especially like this idea since I don't think the dorms are the best places for drinking to be happening (some people in the dorms believe drinking to be really bad and I don't like that if there is drinking in the dorms that they are forced to face it in their "home" however temporary that home may be. I'd much rather see people leave the dorms to drink as long as they are walking/taking the bus but it's based on the idea of respect for people's space.)
6. Another argument: people can vote, be drafted into the army, purchase porn etc. when they turn 18. Why shouldn't they be allowed to drink? This one makes sense, but I will say that for example your car insurance goes down $100 a month when you turn 25 and you can start renting cars then- why? because you've been driving for a while and statistically you start getting in less accidents at that time. I suppose I'd have to look at more of the research about the decrease in alcohol deaths since they changed the drinking age but I think that statistic is more based on the increased amount of awareness we have these days etc.
7. I do really like that people are calling the question. I think it is definitely a question that needs to be raised. I am also proud that education people are raising that question since it's important that educators are aware of what is happening. AND I really like that the question is being asked if we should give the responsibility sooner. I like to hear when people are saying maybe us not trusting people is the real problem? It's good that people are thinking of alternative ways to handle issues.