I know Hawthorne berries, buds, flowers, hips and leaves are edible. I also know that its fine grain and high density makes it burn very hot. I know the would was often substituted in forges when casting pig iron blanks. It also makes beautiful inlays and veneers.
Guess you could set a small dry piece on an open brazier of coals and see if it gave off an unpleasant odor. I don't recollect it smelling bad.
You could place a small pan of water under an overturned No. 10 tin can set to capture some of the smoke and then dip your finger in it for a taste test to see if imparts an unpleasant taste.