In practice, impeaching and convicting a president means shame and humiliation for the impeached president. Politicians don’t like to do that to other politicians. For one thing, it sets a precedent that can be used to unseat a president of their own party. The impeachment process is also likely to be considered partisan and a waste of time by much of the public. So in practice, an impeachable offense does have to be something very like an actual crime, even if the Founders didn’t intend it to be.
Very insightful observations. I am impressed.