Usually only feather over the concrete pads. Feathering over stones and gravel usually end up getting picked up and hit by the blade. Also get loads of dust being kicked up if there isn't a decent wind blowing it away. That's one of the last things you want getting sucked through the PT6.
As for the lack of barriers, I can't explain why there wasn't any there.
As for the Airvan comments, I will pass them on to the Ops Manager. Get him to have a look at them.