Re: Is this structure safe?
At the Indiana state fair collapse, the roof tore away as per design, so it definitely exists.
At the Indiana state fair collapse, half the roof tore away as per design, but the stage right roof skin side remained attached. The wind hammered the structure down faster than the speed of gravity, snapping critical lateral guy cables and straps and dragging weights that other guy cables were attached to.
As Jay mentioned, gust fronts blow every direction, in my back yard saw a thermal "dust devil" pick up a piece of 4x8" plywood and helicoptered it up around 60-80 feet in the air before it spun out of the thermal center and it flew 100' feet away, fortunately not damaging anything.
In another event, the steel roof blew off my guest house, cutting through my neighbor's power mains, the short circuit caused the town's main transformer breaker to trip. When I came home to find the electricity out, saw my fence was trashed, but had no idea the roof was missing until the next morning.
Regarding the O.P.s query, "is it safe?", my answer would be with no wind, it probably is safe, but wind is unpredictable, and worst case scenarios should be anticipated. The lack of any lateral guy wires is a grave concern with as much sail area present on the roof, advertising scrims and suspended PA.
Art