Just keep in mind that there are two things to worry about: getting off the ground, and clearing obstacles. A PA28, especially the -140, is no Ferrari of the air. Your idea of full flap may work if there are no obstacles, but keep in mind that the time needed to clean up the aircraft to climb away may very well lengthen your distance to clear the theoretical 50' obstacle.
Nothing beats knowing your aircraft, and I have operated outside "the book" on numerous occasions, in a safe setting, to learn just what was possible in a pinch. I know how my aircraft operates in just about every configuration including in a spin (it is cleared for it, my Sundowner is one of the rare ones with the aerobatic kit installed). The field where I operate from is 5000 ft of asphalt but I also fly into a buddy's farm that is 3000 ft grass with a mountain at one end, and my home base is infested with deer, so being able to haul it off the ground early may be useful some day (I have manual flaps). But I don't think it should be routine unless you are very, very practiced at it. I do know for a fact with my Sundowner, without flap, any attempt to pull it into the air below 65 knots is futile and quite possibly dangerous, and it will definitely only increase your takeoff distance.