How safe is it to harvest wild sassafras?
I have been cooking with sassafras roots for years, all wild, as taught by my Indian Lore classes in scouting, and what I teach to current scouts.  I also have taught specific recipes with the leaves, but only as flavoring in steaming and such, never eating (not for harm or issues, but because of the bitter aftertaste of the leaves)

As far as your actual questions:


How true is this?
Is there a way to ensure safety in my cooking (beyond scrapping the project altogether)?


For 1, I would have to say that they are true, but also clinical, and I have not been able to discover any documentation that sassafras directly harms humans, only that some of the compounds found in sassafras are harmful at higher levels, and given that the plants are wild, the concentration levels are unknown.

For 2, I would say that one standard root (approx 6 inches in length of varying circumferences) is good for about a half of a gallon to a gallon of water, boiled 2 to three times.   If you want a concentrated flavor, boil the water down, and you will get a more potent mixin liquid.   (also used for making beers, and ales - ginger ale included, both alcoholic and non alcoholic)