Well, there are 2 ways to do the overhead approach.
One is in controlled airspace with a control tower authorizing the maneuver. That's a no brainer - it is good - facilitates traffic flow and is routine at some airports. Do not do it without tower concurrence. Locally, if you call in with an RV call sign, they sometimes ask if you want an overhead break.
The other is at uncontrolled airspace - like Class G. All FAR 91.126 says is all turns must be made to the left unless otherwise specified by light signals or other ground visual markings indicating turns should be to the right. It does not mention traffic pattern, just make all turns left (standard) or right (non-standard). Make the approach in accordance with FAR 91.126.
The overhead break is not illegal. No where in the FAR's is it prohibited. In fact it is an approach and landing procedure used for many years. It has history. But that has to be taken with a bit of common sense because an over head break that screws up normal traffic as outlined in the AIM could be a violation of other FAR's concerning reckless flight. But it could also be argued the complaining guy screwed up the over head approach so there you are, legal limbo.
I like the over head approach because of where it came from. It is a fast, efficient way to get lots of airplanes on the deck using minimum airspace.
If you can do a steep turn and maintain altitude within +/_ 50', you are qualified.
At an uncontrolled airport, make sure everyone in the area knows what's going on, and if need be, give way to the student just learning to fly in a Cessna on a down wind cross-county leg. We were all there once and need to cut these new pilots a bit of slack, or anyone else flying like a new pilot. That's a lot easier than having to respond to a formal complaint. All it takes is a bit of common sense.
P.S. I did not vote because I have a policy, which I tell telephone solicitors, I don't do surveys unless I get paid $100. They go away real quick and do not call back.