What Eddie and Curly Dave said. If you were there before the flying neighbor, just when and how was this approved. Who(FAA and local zoning commission) inspected, approved and signed off on this. If approved officially, ask the planning/zoning commission and the FAA for the approach and departure corridor plans. IF approved officially, I bet there are use restrictions... As mentioned, the planning commission has to have a plan so they know where future land users may have restrictions imposed on them for the pre-existing airport.
Unless you are directly off the end of the runway, there is no excuse for an aircraft to be over your home at low altitude and full power. If your at 1/4 mile away from the end of the runway, and the runway is 1/2 mile long, I would guess that a typical aircraft would be higher than 300'-400' by the time it reached your home on a departure, and should probably not ever be lower on either approach or departure. If climbing in the pattern, I would expect it to be higher. A typical landing pattern starts flying parallel to the landing runway at approx 800'-1000' above runway height and about that far away from the runway(1/4 mile?). The aircraft is slowed at this point and should probably be using little power(just enough to maintain altitude. This is the "downwind" leg. When abeam the touchdown point, power is reduced and a descent is started. It is flown at little or no power to a point where the desired touchdown spot(end of runway) is approximatly 45 degrees behind the wing. Then a 90 degree turn is made toward the runway, while still descending at low power. This flying perpendicular to the runay heading is called the "base" leg. As you approach the runway bearing, another 90 degree turn is made to line up with the runway. This last leg is called "Final". A proper approach is made with little power, and unless really screwed up, never any abrupt power changes as you describe. It is also made with enough altitude so that an engine failure is a non event as you are basically gliding down to the runway anyway.
Unless terrain or restrictions dictate(don't fly over the hospital on the north side of the runway), traffic paterns are typically flown "to the left" with the base and final turns made in that direction as that is what side the pilots seat is on in a side by side configuration. I learned to fly at an airfield with such a restriction so sometimes we flew right handed patterns. So when landing one way, he will fly on one side of the runway, and when landing the other way, he will fly on the other side of the runway. Takeoffs remaining in the pattern are also flown to the left unless restricted and at the same distance from the runway, but in a steady full power climb untill patern altitude is reached. If you happen to fall under the established traffic pattern for this approved airfield, Unless each and every pass over your home is either preceeded by his wheels leaving the runway a minute or two before, or his wheels touching back onto the runway a minute or two later, he is propbably just trying to light your fire as you had the audacity to challenge his right as a pilot to fly
Curly Dave hit the key point. The FAA is a big old school buracuracy. It runs on paper... Letters and official complaint need to be addressed. Phone call? What phone call? The more paper the better. Letters should include photos, maps, sat photos from google earth, descriptions of what the pattern should be based on the airport plan(planning/zoning commission), how your property sets in relation to this plan and how he is exactly flying in relation to the airport and your property. If you can take video, please do so. He might not fly so brazzenly if he sees you doing it though. If photos or video are available, Make sure it is detailed enough to identify the aircraft and wide angle enough to show how he is flying in relation to your property/the traffic pattern. IE: The barn is due south of the house, and he approaches, as the video shows, directly over the barn. If you turn in a video of him flying a normal pattern, you are probably going to get laughed at. The behavior you describe does not sound like a normal pattern though. Abrupt power changes over your home are not in a normal well planned approach or departure. Understanding how the patern is supposed to work will help make your complaint easier to describe in terms that make sense and be more credible, than just some non-pilot whinning about airplane noise...
As with all government agencies, problems are to be handled at the lowest level possible. Start with a letter to the person you have already dealt with. No response in 2 weeks, move up the chain. Once you understand the airport plans/rules, a letter to the zoning commission might not hurt either.
This is a matter of your word against his. "But Mr FAA investigator, I am just flying in the pattern, I don't know why he is complaning" A video tape of an aircraft with his tail numbers buzzing your house and gunning the engine would be real handy after he has repeatedly made statements to that effect.
Being a pilot, I would not be bothered if I lived under the pattern and he was operating in the pattern as I described above. I would have no right to be if it was an official airport. If he was not, I would have my videocamera charged and ready, and a plan for best capturing any events on video without easilly being observed from the air. I would once again go visit him to express my concerns with how I feel he is operating his aircraft over my home and disturbing my right to peacefull enjoyment of my property. No threats, no what-if's, no "I'm going to...", just express what is bothering you and the distress it has caused your family. Then I would set back and wait. If the guy is trying to annoy you, it will intensify. As a pilot, he dosn't have the right to deviate from approved patern procedure except in case of emergency. If he does, well then he deservs what he gets.
As a pilot, if I had my own runway, I know it is a big sky up there. I am fairly certain that I could work out a noise abatement plan with my neighbors. I know I hate being disturbed, I would hate to disturb them any more than necessary. But where I think flying is necessary, they do not, and that is where the comprimises would need to be made. I think it would also be bennefficial if they understood the needs I have to remain safe in and around the traffic pattern. As a pilot I am under a lot of scrutiny. The last thing I would want is the FAA or zoning commission crawling onto my back because one of the neighbors thinks I am buzzing his home...
Good Luck