Scenario: Dr Doom fires an Energy Explosion off at an Ultimate Thor with adjacent figures. Doom hits Thor, but Thor's Impervious absorbs the damage, does he still give off splash damage to adjacent figures?

According to the PAC, it says that all characters adjacent to the target sucessfully hit take the splash, so I assume that despite Thor not being delt damage, he was still hit by the attack and should still give off splash.

Yes they would take damage. It was a successful hit but Impervious reduces damage to zero so all that were successfully hit take splash damage.

Now if it was super senses and he made the roll then it wasnt a successful hit and no one would take damage