1) They aren't sure just how beneficial it is, and even if what the studies show is correct, smoking it for recreation probably isn't terribly good for you anyway.
Aren't there other, more safer ways to use it besides smoking though?
Yes, like the oil rub referred to above, though that probably wouldnt get you high. It would be very irrisponable to release a narcotic without knowing its full chemical dynamics. The debacle that happen with LSD from the sixties and seventies shoudln't be repeated again.
The effects of Marijuana are probably more well known and more studied than some of drugs that are pushed out onto the market by pharmaceutical companies.
As for safer ways for getting the effects of marijuana there are a few ways aside from those mentioned already. It is fat soluble and one can make cannabis butter to cook with it. It has been put into pills, and I think it is soluble in alcohol, but mixing it with alcohol probably isn't something you'd want to do if you were looking for a healthier approach.
I've read a lot about marijuana over the years due to dealing with pain for the better part of my life. I've spoken to people who've used it medicinally and have heard great things about it. I know some people who use it to control nausea and as an appetite stimulant, and others who've used it to control pain. On the other hand I've known some people who've tried it for pain management that did not like the way it made them feel.
I really feel that marijuana should be legalized. It has been demonized for so long that people disregard it off-hand without thinking critically about why they don't agree with it. A lot of people think that anyone who uses it is a lazy pothead. While I'm sure the stereotype holds true for some, I think that it doesn't really represent the larger whole. I've met a lot of successful people who use it. It is a plant that helps many people bear the pain and sickness a lot better than they could with conventional medicine. However it is good to know that there has been headway made. If I so desired I could go to my doctor and get them to write me a letter that would allow me to obtain marijuana, while it still not entirely legal, it is tolerated. It is of course not without its downsides, but then that is true for a lot of things that are legal.