First of all, let's make it clear that there is far more abuse in this country with legal drugs. Things like oxycontin and other painkillers are nothing but legal opiates that are abused far more than recreational drugs. That said, there is no reason why almost all recreational drugs should not be legalized and regulated. It would destroy the black market for the drugs, and stop the resulting violence. Plus I don't think it would create any more drug abuse than exists today, and it would be safer.
I don't believe that oxycontin and other pain killers are abused more than other drugs like coke and such. I also don't agree that we should just legalize anything and everything. You can't say "it worked in that country so it'll work in ours" because Americans are a people of excess much more so than most other countries. I'd prefer that drugs weren't legalized, but I realize that if I'm in the minority then what I want won't matter.
Yeah, they are. Legal painkillers are destructively addictive and an awful lot of the people who end up on heroin, or other opiates, got their start on legal opiates and turned to the black market route when their prescriptions dried up. Legal opiates are a dangerous rabbit hole because they are so misunderstood, but nothing is misunderstood more than marijuana, which is ridiculously benign compared to alcohol.