Who is an important individual in the Watergate Scandal and what were their actions?

I think that many figures can be identified, but why not go for the most important one in the President, himself?  Richard Nixon has to be seen as one of the most important figures in the Watergate Affair.  Even if one could concede that there was no incontrovertible evidence that stated that Nixon authorized the break- in at the Democratic Headquarters, it was painfully clear that the President authorized the cover- up and the concealment from the public as to what happened.  Nixon's own mentality that fostered repression, silencing of dissent, as well as a "law and order" belief that erred on the side of repressing individual rights are all direct actions that marked Nixon's tenure as President.  These all filtered into the Watergate Break In, ensuring that the Affair was a direct and logical extension of President Nixon's belief system.  President Nixon's direct action of enabling the break- in and then directly engaging in the cover- up of it are actions that are linked to Watergate.  Certainly, the President, himself, did not break inot the headquarters.  Yet, the action smacked of what the President had permitted under his leadership and the cover- up and seek to evade responsibility from it are his actions and what can be directly linked to the affair, in general.

Apart from Nixon, who else was a key player in the Watergate Scandal?

In terms of the anatomy of the incident and its implications on American History, then- White House Chief of Staff H. R. Haldeman could be considered by many standards to be an overt actor in the Watergate Affair.  Haldeman actively discussed with President Nixon how to deal with the effects of the crisis.  Both men are captured on tape using the CIA to stop the FBI's investigation as a way to impede a transparent disclosure of the incident and further a cover- up of the affair.  Haldeman was overtly responsible for doing all that he could to ensure that the President's knowledge of the incident would remain hidden.  Haldeman's ability to use other agencies to deflect criticism of the White House and prevent a fuller understanding of the Watergate Affair would have to make him an individual whose actions would be overt in obstructing justice and consolidating the power of the President to be above the law.  I think that this is where Haldeman would be considered an overt agent of action in the Watergate Affair, representing how the desire to keep and consolidate power usually leads to more bad things than good.