Daredevil Run not appearing
According to the Mario Wiki:
This mission can only be played after two conditions have been met: the player needs to have collected the Comet Medal from the previous mission and the player needs to have 9,999 Star Bits stored with the Banktoad. Completing both conditions will cause the Prankster Comet to appear, allowing the player to play the mission.
Make sure you have 9,999 Star Bits as well, if you got the Comet Medal already.