I completely agree with the fact it's illegal because the gov't can't tax it. It's easier to grow and cultivate than tobacco and alcohol, so if it were to become legal, people could just grow it on their own and not buy it.
I think it's just as harmful as cigarettes, if not less. Definitely less harmful than all the other illegal drugs. I do believe it helps with symptoms of somethings, and chemo is definitely one of them. My uncle got through it very well, and he always thanks pot for it.
Tell your dad good luck and he'll definitely be in my thoughts!