Pretty good assessment. Nixon was basically a good man and had no knowledge of watergate. His downfall was really a minor event in that he tried to cover it up after he found out about it.
The 1971 commutation of Jimmy Hoffa's sentence and release from prison, for example, seems beyond question to have been in exchange for a series of large cash payments from the Teamsters to the Nixon campaign and political operations, with the Teamsters also endorsing Nixon for reelection. At the time, Frank Fitzsimmons and his mob allies were in control of the union and enemies to Hoffa. Notably, Hoffa's pardon and release from prison included a requirement that he refrain from any union activity.
There is reason to think that Teamster cash was used to finance the Watergate burglars and that some of it may have made its way to Nixon's immediate personal control and use. Providing a direct quid pro quo of government favors in return for cash is the essence of bribery, with the case stronger if the cash goes to personal use. I think that Nixon especially feared such inquiries and criminal charges based on them and covertly bargained for a pardon in return for his resignation.
Above all, Nixon knew that even if he might defeat impeachment by showing that other Presidents had done as much as he did and far worse, such an argument would have been unlikely to defeat criminal charges arising out of the Hoffa commutation and other misdeeds. And, even if it did, he would have been financially and personally ruined.
Nixon was in fact a better person and President than Kennedy and LBJ were, and they were guilty of far worse crimes than Nixon was. In an odd way though, by getting caught, Nixon may have done more for the cause of reform than he would have attempted had he remained as President.