Bingo! Trump has lost all interest in any matters involving the FBI, Obama, Clinton’s, etc... Sessions has done nothing to help Trump in any manner. Trump seems satisfied so that is how it will stay.
I believe you are correct in that Trump is being blackmailed(or sililar). It probably leads to his Taxes because the worthless IRS Director is still in place and no moves have been made to eliminate the guy.
I’m guessing Trump’s going to wait until the ‘Russia Russia Russia’ thing is behind him. Then he will fired every damn last one of ‘em.