Absolutely right on all your points.

To further your example - Lincoln didn't include four Union states and three occupied areas of Confederate states within the Emancipation Proclamation because it was politically expedient - along with the suspension of habeas corpus and several other dubious practices.

To provide another:
FDR sat on his hands for the early part of World War II, was accused of war profiteering early on and could be seen as only getting involved because we got attacked.  Once in, we ended up with Japanese internment camps and look-the-other-way law enforcement when violence rose against anyone with a remotely German or Italian accent.

Several of the Founding Fathers were slave owners, and some others are accused of being womanizers/misogynists.  Alexander Hamilton was a gun-toting murderer by current standards.  McKinley could be called a racist and imperialist warmonger for his Philippines acts. 

If we start down this road... it'll get ugly fast.