Joe,
At the last place I flew I was told by our safety officer that Hovering over the runway while their are other people in the air is kinda distracting to them. I tend to agree even though it was me they were talking about. I agreed to only do the low TR's and hovers over the runway while there was noone else in the air. If I was flying with other people in the air I would just do them a little farther out.
If people know what I wanted to do they'd stay out of the air for the 10 mins I was up. Just common courtesy. Same couretsy we gave a fellow Heli flyer who wanted to do aerobatics with his helicopter over the runway. We all just landed and let him go at it.
Did you know Helicopters can hover also??