Those are good points, although on the last part I would note that frankly the tobacco companies support the War on Drugs, including laws against marijuana, simply because they theorize that if marijuana were cheaper to buy (as it would be if legalized), people would buy less cigarettes. Actually, maybe that's the alcohol industry. From what I understand there's a high correlation between smoking and the use of nearly any illicit drug.
Actually it would not surprise me if in the near future the tobacco industry comes out for marijuana legalization at least. For a start they have the ability and means to deliver goods at a mass level, unlike say the illegal growers and secondly Marijuana has nowadays a far less social stigma than tobacco does; despite the former being illegal (in name only if we are being honest; but the establishment, WTI, would like to think otherwise.)