For example, tobacco on it's own is relatively harmless - the side effects of smoking are mostly caused by tar and nicotine. Alcohol is relatively harmless even at a pint a day level. Alcohol is only a danger when people exceed limits, or drive whilst under the influence.
Weed does however cause paranoia issues, which can easily spiral due to it being a dependence drug to make people feel better.
I reckon that Medical Marijuana, in the form of pills, at a low dosage, should be legal. However there should be plenty of restrictions on it to stop recreational use and false prescriptions.
A lot of flaws?? How? It is nothing but true hard facts that the argument is constructed upon. Nicotine is IN tobacco. Tar is a byproduct of the combustion. You are right that alcohol is only bad when consumed in excess... but that is not the point of the argument. The rate at which people form literal, physical dependencies on alcohol is much higher that of marijuana(zero, by the way.) Tobacco and Alcohol actually impose significant health concerns upon the consumer. Also with tobacco claiming around 5 million annually, alcohol roughly half of that, and marijuana with not a single one in all of history.... The health issue kind of becomes a big thing. Especially with tobacco causing cancer and cannabis showing curative properties towards it.
Weed doesn't cause paranoia, either. If you're a paranoid person before, you'll be one after. The increase in paranoia is merely due to the fact that you are, indeed committing a crime. If there was no legal issue... people would have nothing to even be paranoid about. Not to mention the prominent number of people who already are not paranoid because they really don't care to much... Also... what do you mean by "dependence" drug? I have not met, or have found one single instance of recorded history where someone has become "dependent" upon Marijuana. There are a lot of people who ruin their lives over weed, yeah. But that is bad decision making on their behalf, nothing to do with the actual cannabis. Thus, your argument falls flat.
I'd also like to point out... that the U.S. is one of the few countries to actually ban industrial hemp. The regulations surrounding this are only evident that the ban is to keep corporate cronies happy. While it is illegal to produce such goods... you can import processed forms(paper, material, oil) and sell them in America/put them in your products. This shows that they do not believe the plant to be bad(or they would block imports on it to) but rather that they other, shadier motives.