I feel rather hypocritical urging
@Senior Space Cadet not to launch his dirt dive recovery rocket, even on a deserted soccer field miles from anyone, while saying this looks like a cool experiment and eagerly waiting for the results. I assume you've got a 'chute or streamer in there, but that's not the point. It looks potentially dangerous, to a significantly greater (if not very large) degree than most of the rockets any of us launch.
You're certain that tension in the strings keep them rigid enough to transfer force to the body, but I confess I'm skeptical (not that I'm anywhere near sure they won't). You're not so sure it will work that way after burnout, and I have very little doubt on that part; it won't. (You aptly point out that at that point it's a hazard only to the rocket, assuming a 'chute or streamer deploys.)
Still, because of the substantially larger than normal chance of totally unpredictable behavior immediately upon leaving the launch rod,
please don't launch this anywhere near other people.
Do you plan to prop the drive section up on the rod so that the ring is dangling, i.e. the strings start out straight?