I'm surprised this topic doesn't get more air play.
Mate of mine got caught with a small amount of weed and pipe in WA, he got the option of going to an intervention counselling session and avoid going to court and criminal conviction.
So he goes to the intervention counselling session and describes how he smokes one or two small cones in the evening, smoke a pack or so a day of cigarettes and a bottle or so of wine at night.
Well, councillor admits that his cigarettes contain far more toxins than weed so is far more detrimental to his health and wine consumption is rather excessive and also more detrimental.
Bottom like is moderation, being stoned at work is not safe just as being drunk is not safe but if your in the advertising industry a bit of weed does help creativity.
Hemp is another story, fast growing on even marginal land environmental sustainable that can be used for heaps of every day products.