Uhmm, that didn't happen with Clinton though. Regardless, I would have argued that Clinton should shut down her foundation while president if that had come to pass.
As for $1,000 a night, are you seriously arguing that he can't be corrupted in that way because he's already rich? First, his own history shows he's willing to violate the law for extremely petty sums of money, (look at Trump University, all the shady self dealing with his charity, etc) second all of human history shows that rich people are just as easily corrupted as anyone else, maybe more easily.
Keeping your eye out isn't good enough because what he's doing is ensuring that you can't keep an eye out because you won't see it happening. You'll never know.
Can you elaborate on that? As a general rule of thumb I outright reject bogeyman arguments or arguments that make the opposing argument seem like the only correction argument, absent any rational reasoning behind it. I think it would benefit the skeptics if you were to do that.