"As for Trump, I expect it is technically and practically (not to mention, politically) impossible for him to be charged with sedition in relation to acts he committed during the period he was President."
I would not be so sure about that, it's unprecedented that a former president to be charged with crimes however Trump efforts to overturn the election and have himself installed as president is also unprecedented.
Nixon did face the prospect of being charged with crimes but Ford gave him a pardon other wise he may well have been charged
After Ford left the White House in 1977, he privately justified his pardon of Nixon by carrying in his wallet a portion of the text of Burdick v. United States, a 1915 U.S. Supreme Court decision that stated that a pardon carries an imputation of guilt and that its acceptance carries a confession of guilt.
Yes there is issue in trying to charge a sitting president but nothing to suggest they still have protection once they are no longer in office
