Geeeeez! You don't even know what Nixon was or wasn't guilty of and yet you're out here saying he was actually guilty of some things.
He was .. but you should know what they are. Nixon was guilty of covering up the break-in. Nixon didn't plan it, and he didn't know his people were planning it. I don't think he would have approved of it .. but when he found out what they had done .. he chose to hide it.
It was a very big mistake. He should have exposed them and fired their butts!
It never was conclusively shown one way or the other, as far as I could tell, if Nixon knew about the break-in in advance. Remember the June 17 break-in was the second break-in, intended to replace a tap that was not working. John Mitchell was in charge of people involved in Watergate, and was also having frequent conversations with Nixon. Nixon had a reputation for micro-managing. There were conversations between the two of them which were never released, as far as I know, so it's possible that Mitchell told Nixon...but perhaps not, to provide "deniability."
The other thing is the 18 1/2 minute gap...it's almost certain that it was erased by human action, and the official version of Rose Mary Woods doing it accidently was always very dubious. It may well have been Nixon himself who discovered that there was explosive material in that part of that tape and erased it himself...I believe there were handwritten notes (maybe Haldeman's) from that conversation which indicated that the topic of conversation was Watergate during the time period that the erased tape covered. We'll never know--those who might have known are dead now.