I didn't see anything in those maneuvers that would stress out the wing boxes. Essentially, he performed a number of Vx demonstrations with a roll over to let the nose drop and recover airspeed after each one. In effect, he simply traded airspeed at the bottom for altitude at the top, and then rolled it over to let the nose drop through the horizon, which makes it impossible to stall.
The co-pilot was almost certainly a high time aircraft commander and he was referencing entry speeds prior to each Vx climb, using the term, "Continue" if he saw equal to or above the pre-brief required entry speed. Then the pilot flying hauled the nose up and referenced speed bled down likely to Vx and then pushed the nose over to level and then continued with the 60 degree bank and let the nose fall through horizon.
The one time I thought he took it to the limit was toward the end when he got the stall indication, but he was wings level and already applying power and pushing the nose down. So, in effect, he was already engaged in the straight ahead stall recovery before the stall alert was sounded.
The he reversed and did a power off approach to land.
With a C-130J, no cargo, and most likely a very light fuel load, near sea level at Paris, he had tons of power reserve and composite props that generate lots of thrust at the low airspeeds he was flying at, which meant the forte of the Herk came to the fore -- the aircraft generates excellent thrust at low speeds because of the nature of turboprop aircraft. So, speed recovery was quick. The highest climb angle he achieved was 60 degrees, which was reasonable. Throw in the 60 degree bank at the top and being nearly overhead the cameraman on the ground and it looked like he did a loop, but he did not.
Good flying!
Ken