How far was Watergate common practice for behind-the scenes political maneuvering of its time, or was it a completely out-of-the-ordinary unthinkable act? By being involved, was Nixon acting like an out-of-control tyrant, or just a shrewd politician who was just unlucky to be caught by a scandal-hungry media.
By itself? Nah. Nixon was not the first or last President to preside over breaking and entering for illegal wiretapping, or worse. He was only unlucky enough to be the first President for whom J. Edgar Hoover demanded a written order for such things-that's part of why the Plumbers came to be. Nixon was stupid and paranoid enough to bring it into the White House. As John Dean said, the Watergate break-in itself probably really was nothing but a third-rate burglary, ironically. (Nixon also celebrated it at first, but by 1973 realized that Hoover's death was a very bad thing for him.)
Now, when we include other scandals caught under the web of Watergate, yes. You see just how out of control this administration, and really the government as a whole, was by the Nixon era. It had accumulated for decades, and the bill for the Imperial Presidency was due. But rather than perhaps change with the times, Nixon doubled-down to an extent even beyond his successors. Nixon wasn't unintelliegent-he knew there were shady things going on his administration. He kept people around that he knew pandered to his bad side, men like Colson. He just had a fatal attraction to that kind of stuff.
Nixon was not scared of Watergate itself, but what it could reveal, for a reason. The 1969 NSC wiretaps, the Ellsberg break-in, the Moorer-Radford Affair, and what was one of the blatant proposals to violate basic liberties ever, the Huston Plan. Nixon was addicted to secrecy and control to an extent unhealthy for a democratic leader. Nixon ruled intentionally in a very... Gaullist fashion, which was a hazardous thing to do in American politics at any rate, and to boot at a time where there was such a backlash to it. I'm not suggesting that other Presidents were saints or that some of Nixon's enemies didn't have less than pure motivations, but the fact was that Nixon ordered an obstruction of justice. That was an illegality, and that was grounds for impeachment.
I'd recommend this link. It delves into the historical background a little. America had changed dramatically in those years, and with a President that sought to expand rather than curtail the Imperial Presidency, a clash was coming.
EDIT:
It is true that secret back channels independent of the State Department and other parties were necessary for the unquestionable foreign policy advances of the Nixon Administration. I'd be the first to point that out that the bureaucrats were and are a serious problem for any President who wants to actually reshape foreign policy. But rather than return to somewhat more normal governmental processes, as a form of post-Vietnam reconciliation, Nixon seemed to be ready to ratchet it up after the election, to get more power for the President.