You're right.

While we're at it, we should make sure no one goes up to the massive speaker system and puts their ear right up to the speaker cone too.

The beam is not going to be tightly focused, if it needs to cover a big chunk of a stadium at once

Yes. The manual from the manufacturer recommends wearing specific green tinted safety glasses if you are standing closer than a meter to their transmitter while it is on.

I guess this device can be modified to take visible red lights with some redesign, if you'll be really concerned with that.