If you don't propose to destroy the US justice system, you seem to have an enormous confidence in your ability to determine when exactly it should be just ignored. Maybe there are courts and legislative bodies in a democratic system, who are supposed to rule on such things?

Oh yes, sure Snowden could refuse. And the Russian intelligence services will, out of the goodness of their hearts, just stop asking.

Any connections between Russia and Snowden may have been investigated, but the results would not have been made public. That can wait until a trial, at the very least. But again, Snowden didn't stand trial, he defected to Russia...