The pilot reported that while performing a high speed taxi to evaluate an erratic airspeed indicator, the airplane began to porpoise, so she performed a takeoff and maneuvered the airplane around the traffic pattern to land. The pilot was distracted by the other airplanes in the traffic pattern and did not perform the landing checklist and felt "behind" the airplane. On final approach, she pushed in the throttle control to correct for a rapid rate of descent; however, the engine did not respond, and the airplane landed hard in the gravel short of the intended runway. After the impact, the pilot noted that the mixture control was fully out, and she stated that she may have pulled out the wrong engine control during the approach. A witness on the ground reported that the airplane descended rapidly in a flat attitude with the propeller rotating slowly. The witness responded to the accident scene and noted that the mixture, throttle and propeller controls were all pulled out and that the pilot could not explain how that happened, but she did explain that she was very distracted while flying in the pattern. The pilot stated that she had not flown for about 8 months and had no intent to fly that day. The airplane sustained substantial damage to the fuselage.