1) He is under investigation largely due to the BS dossier, that led to the FISA warrant, that led to the unmasking, that led to the investigation.
2) Mueller said he was going to go after ANY corruption he found. He has shown this with Manafort, Podesta, etc... If he is true to his word, then he has to look into Comey, Clinton, etc...
False, he is under investigation because of the lying about meetings with Russians that led to reasonable suspicion that criminal activity was afoot.
What corruption do you see with Manafort? I agree this guy Podesta (not HRC's campaign manager) should be investigated.