Actually, the potency of the product is tested at medical dispensaries in CA, not by regulation, but in practice. When John Q. Grower brings a couple pounds into a dispensary, it is tested, as the dispensary does not want to buy ragweed.
Edibles are difficult, as if baked into something, the temperature can alter the active ingredient.. if too high it is degraded, but too much heat only decreases the THC/CBD and does not raise it.
Concentrating by using butane or another solvent to make oil is extremely dangerous and is now illegal for individual growers in CA.
People I know fill a crock pot full of bud trimmings and melt butter into it. THC is not water soluble, but soluble in fats. So making cannabutter is simple and safe, and is used in baking and cooking. But calibrating dosage is sort of by trial and error, so is not something for beginners.
Not so sure that regulations will ever do much, as once growing and possession is legal, anyone that can grow a geranium will just grow their own. City people, I guess, will mostly buy theirs and will need some safety regulations in place, and will of course pay premium for that peace of mind with taxes, etc.