Just a few thoughts, before supper.
You can only get a pardon for a conviction.
Law is a bluff. If I tell you something and you obey, I won the bluff. I gave a pardon to someone, you accepted it. It is over. Think about Ford.
As stated Congress can issue immunity for testimony only to them. Your fair game to everyone else, if they want you.
Federal Judges have more power than the President to inforce their rulings. Newt wants to arrest them: that will never happen.
As far a RICO, I have no problem understanding how all this started and will give it later.