Until there's some evidence of actual wrongdoing (threats, illegal financial transactions, etc) this is completely irrelevant. Trump is a bad President, but even if this whole story is true, it has nothing to do with his (in)ability to carry out his duties, nor the reasons he should be removed from office.
This is true. That being said, this is another one of those fun "Imagine how Fox would have reacted if Obama..." scenarios.
Yeah.
That said, it is literally inconceivable to me that Barack would ever cheat on Michelle, whereas Trump is already confirmed to have cheated on three of his three (that's a running total) wives.