I don't really consider them dangerous. The poisonous parts taste terrible. I've eaten the occasional bloom with no ill effect, but I wouldn't recommend it, just in case your variety differs.
I've done exactly this. It is also possible, at least with some strains, to cut a large wrist stick in the fall, over winter it around 45 to 55 F in wet sand, and have it take off and bloom again the next growing season.
My understanding is that some varieties will self seed profusely of the right pollinators is present. I produced a lot of seed by hand pollinating, however none of it seemed inclined to survive our winters.
Datura on the other hand self seeds religiously, and I've find some really nice specimens growing in fields and other disturbed ground.
Now, about those horses?
View attachment 4150225