The biggest Fallacy ever is that you don't harm others...
Over a thousand innocent people have died in the border towns of Mexico this year so that some folks can use harmless drugs...
Every choice a person makes with regards to using 'harmless" drugs should be mindful of the real cost of their choices. That is the proper spiritual context IMO.
In so many ways it's like the prohibition of alcohol: I say legalize it and tax it in order to diminish the effects of the black market. I agree with your point that it's important to consider the fullest range of effects, but simply put, many folks don't
harm others with their choice to imbibe. Of course, that all depends on where it's coming from. It also depends on the individual's choice on whether or not to act responsibly in other matters.
I'm always shocked at how against marijuana people are, while at the same time holding no problems with booze. Alcohol kills very easily; marijuana doesn't. Alcohol impairs inhibitions and motor skills; marijuana doesn't, or if it does it's a minute fraction by comparison.
I've said about all I can think to say on this subject so I'll probably quit after this. I don't like playing devil's advocate for things like this because I would hate to be the one to compel a person to do something they could later regret. On the other hand it was discovering the BS surrounding anti-pot ads which caused a huge contempt in me for the war on drugs and which caused me to question other far more valid warnings. Those ads did more harm than good in my neck of the woods. So, with that in mind I'd just like to finish with the idea that in all things moderation is key and that personally, as a guy who smoked pot regularly for well over a decade, I don't think it will make much of a positive effect on anyone's aikido training...no more so than going out and getting drunk will, at any rate.
Take care folks and be careful!