Yes I do really think that marijuana can medically help people. Definitely! Especially cancer patients, for both pain and nausea.
And their are differences between cigarettes (Nicotine) and Marijuana (THC) for one nicotine is classified as a stimulant which stimulates brain cells and elevates the heart rate. Speeds up metabolism. Marijuana is classified as a hallucinogen, which creates a feeling of euphoria. Nonetheless the addiction to nicotine is by far worse than addiction to marijuana. Therefore making it much more difficult to detox the nicotine than THC.
As a matter of a fact the only similarities the two share are that 1. you can inhale smoke from both, but marijuana can be used in other ways such as eaten, vapor, pill etc. unlike nicotine which can enter the body by patch and or by gum... and 2. a marijuana joint resembles a cigarette. That's it!
I am not encouraging the use of marijuana especially the use of illegal marijuana. I am just simply answering and responding to your post. And stating my personal opinion.