No. There is no reason to think he would want to, but even if he did, the US has long had a system of laws and courts that protects the rights of all groups.
Yes, they did and all historians would agree that the Soviets did commit the massacre at Katyn.
President Obama has not been accused of any felony.
Someone who has committed a massacre is commonly referred to as a mass murderer or spree killer. These terms describe individuals who have intentionally and violently taken multiple lives in a single incident or series of incidents. People who commit such acts are often considered to be extremely dangerous and mentally disturbed.
Richard Nixon
John Quincy Adams did not commit suicide. He died at an advanced age from a stroke. No US president has ever committed suicide.
for protecting them, by mock trial, from punishment for any murders which they should commit on the inhabitants of these states
yes he/she can if they commit a crime
yes of course specially on live interviews or press conferences. nobody's perfect. even presidents commit errors.
First Trump would have to commit an impeachable offense (which he hasn't yet), then be impeached by the House (unlikely since it is controlled by the party that nominated him as their candidate), then convicted on articles of impeachment by the Senate (also unlikely for the same reason). If Trump were no longer president then the Vice President (who will be Mike Pence) would assume the office of President of the United States.
Well, his death wasn't a genocide, and he didn't commit genocide, but I suppose you could consider some of the things that he believed in and supported genocidal. The group that he belonged to is said to have committed rape, murder, and torture as well as promoting the slavery of non-Islamic women.
you cannot run for president if you commit a crime or ain't born in usa.
Commit troops and resources to repel any armed attacks