I would say your annealing is failing because the part is so small that it cools too quickly, even in free air. Place it on a piece of 1/8" or 3/16" steel plate and heat it from the underside. once the plate and spring are the correct color put a cap over it and let it cool over several minutes. You can heat it the same way for tempering and push it off the edge as you mentioned. You can even draw it back the same way, carefully!! The plate just gives you much better control of the heating and cooling for such small parts.