'Fan' works more effectively as psychological drama than suspense thriller. As the latter it's suffering from major plausible issues while as the former it's sufficiently deliver a message about moral ambiguity. Tad over-the-top at some points, but SRK nailed it.
Doing another Darr, eliminating the female lead and giving himself two starring roles is probably about the most SRK thing SRK could have done. For him to then skewer his own legend by unflinchingly playing the stubborn megastar jerk he actually is irl, though, was totally unexpected. Sadly the movie derails after a point, but the negotiations on where stars' and fans' boundaries should/do lie are v v interesting.