There is no question that re-opening the FBI Investigation into Hillary Clinton’s email server is a big deal. The FBI normally avoids acting just before an election in order to avoid charges of political manipulation.
Personally I am leaning to a combination of Theories 1 and 2. Comey is doing damage control for the harm he’s caused to both the FBI and his own reputation while simultaneously keeping a lid on Wikileaks.
Comey is a Clinton surrogate of that there’s no doubt and frankly he cannot be trusted to act in the interests of justice.