Ruby protected nobody, and thwarted a possibly avenue of information on the Kennedy assassination.

Snowden has done a service to the world, revealing the threats they're under (through both the NSA and any other entity which could exploit the weaknesses they use), and promoted a great deal of relevant and useful information into the public discussion. As you've just conceded.

Snowden may have broken regulations, and may have broken laws. But he served both the US Constitution, and the cause of Justice. Regulations, laws, and the NSA, serve the Constitution and justice. A pardon is a means for correcting instances where laws fail to serve justice.

Your comparison makes less than zero sense.

In this case, people were knowingly breaking the law and stamping "confidential" on the evidence.

You can't just go about breaking any law and cover your tracks by labeling it with something you paid $4.99 for on vistaprint ... what an absurd position to defend.

Because making public the knowledge that our government is illegally surveilling the entire population is in the public interest. He tried to stop violations from within, and when that was ineffective he used the only other recourse he had.

Did you just compare murder to whistleblowing?

I don't think the comparison with murder is justified at all.