Are you sure the brake disc isn´t "warped"?
Spin the wheel and just Slightly apply light force to the brake lever, and maybe you will notice the pads touching the disc.
But on the other hand, sometimes the pads seems to touch the brake disc when I pushing my bike around at the parking lot, or similar, but i don´t feel anything strange when driving. No hot disc, no pulsing in the brake lever either.
Clean the caliper and every part you can reach, thoroughly, with Brake cleaner or similar.