America sounds like a hellhole for buying weed if your experience is indicitave of the general experience. I’ve smoked a LOT of weed in oz (and Canada and Japan and NZ for that matter) and it’s never been like this… probably a result of the cut-throat nature of being the enemy in a war.
Here you’ll occasionally get weed which has not had the hydro nutrients flushed properly (most people can’t tell that though) but you don’t really get pesticide-laced weed because 90% of grows in metro areas are indoor, under lights. The worst that any caring grower will use is pyretherins. I know this is different over there though, where a lot of the supply is grown in national parks using chemicals that are banned for use in most places.
I’ve also never been threatened or pressured to buy. Medical marijuana is a good thing, but I’d say that the cause of these dealers being cretins IS the DoJ and its foolish war on weed. I feel for you though and am glad at least you have options now. I find the biggest stoner dealers will usually have decent and reliable stuff because they smoke it themselves.