About Dutch and American drug policy:
Yes, of course there are countries with a lot lower drug use rate. But I bet this is a cultural thing. It is a fact that the drug war has negligible effects on controlling drug use. It failed completely in the US, for example: drug use didn't go down in general just because it's illegal. In the Netherlands, when pot was decriminalized, the percentage of people doing it didn't fluctuate much, as you pointed out. That makes me believe that making drugs legal or illegal won't do much for controlling drug use.
I'm sorry for not citing any sources for the info I provided here, but one can always Google it.
About point 1:
People have distorted views about marijuana traffic in the US: a lot of it is made by middle-class citizens, who grow their own pot and sell to friends (specially in California). This is absolutely non-violent.
Unfortunately, because of current drug laws, the great majority of the drugs still come from violent, armed drug cartels. Unfortunately, that violent nature of drug trade is unlikely to change for some drugs (like cocaine), since so much dirty money is made from it.
Yes, there are very serious, very rich, very organized drug cartels. Many politicians and other powerful people are involved with drug money, and the drug cartels' influence in world politics is enormous. That is the main reason why drugs are still illegal. Legalizing drugs is not appreciable by the giant, violent drug cartels. It is only appreciable by the users themselves, and should be appreciable by the whole society (which unfortunately is not the case, since the big media successfully makes it's case for keeping drugs illegal).
If drugs were legal from the start, today it would be probably be taxed and opened up to companies like any other business. No problems with that!
This is a good read: http://www.drugwar.com/howmoneyworks.shtm
Well, about points 2 and 3, I very strongly feel that they are inherently associated with drug legalization.
I do agree that legalizing drugs is very hard to legalize. That is so because of the big cartels influence in the world. I strongly feel, however, that it should be our goal.