This is not as clear cut as you would like it to be. Remember "Plame affair"? Compare motivation behind actions of leakers, measurable damage to identifiable people, importance of leak in the eyes of public, political significance of leak. And next compare what has happened to Libby to what can happen to Snowden. And tell once again that Snowden is not persecuted because he is an enemy.

You seem to believe that a person who believes robbing is okay in general, and a person who believes that they themselves should perform a particular robbery have no differences in opinion.

On the contrary, I believe that nobody can be prosecuted for saying robbery is OK, but one can be prosecuted for actually committing the robbery. That's the difference - opinion vs. action. Snowden's problem with the law is not opinion but action.

That seems to not be "on the contrary" at all. You don't seem to believe differences in action reflect differences in opinion.

No. This is like if I witnessed the police commissioner bludgeoning someone to death with a diamond-encrusted poker, took the bloodied murder weapon as evidence to show to media, and was then accused of being a jewel thief who should face his crime.

You got lost in your metaphors. Revealing secrets which Snowden signed not to reveal is a crime by the laws of USA, and this is what he is prosecuted for. Showing evidence of a crime, on the contrary, is not a crime and you can not be prosecuted for it (though you might be prosecuted for tampering with the evidence and obstructing justice if you take stuff from the crime scene and bring it to the media). It does not matter in this case if you condone his actions or not - the law does not say "it is forbidden to reveal national security secrets unless you really-really want to and guys on the Internet are OK with it".