Mana, and anyone else still arguing at this point;
1) Melee while casting, as proposed, is impossible in every sense of the word. If it was possible through ghetto coding and such, it still will not happen, so it stays as impossible
2) If your original goal was to give RDM different melee options, please start another thread, as this thread is specifically about the concept of meleeing while casting.
^ That topic is closed, answered, done.