bending the rotor violently
Violence? I spent literally HOURS taking the disc off, putting it in the vice, bending it this way and that, marking the rub-points with black marker, re-fitting the disc, etc etc etc. Figured out that i was just over-bending it one way then the other. In the end i ditched the vice and spanner and just left the disc on the wheel and coaxed it into line with my FINGERS. worked a treat!
Mind you about 1/3 of the disc was rubbing the pad, i can imagine if its more of a short sharp kink you might need a spanner to get it straight but if its just a gentle warp then try with ur hands first otherwise you risk making mincemeat out of it!