I for one before playing with a mind would want to know the submissive I am playing with extraordinarily well. I would want to know of past abuse particularly in a Age Play or Rape Play situation. You have a mandatory responsibility for the well being and safety of the person with whom you are playing. No discussion on that point and no correspondence entered into. You both have a responsibility to be total open and honest and set out andy and all problems that might arise and make those problems known to each other.
Communication is the absolute required ingredient of success and fulfilling play.
It doesn't work any other way. EDGE PLAY is also merely the action of extending the boundaries of play by offering new challenges, physical or mental, to the Edges of play you and your submissive are already familiar with. Unexplored territory, unfamiliar ground, a step into the unknown. It may be as simple as moving from hand spanking to crop. It could be staring into the abyss and beyond, facing or releasing inner demons and beasts.