It's pretty absurd to suggest we would kill people just because we caught a spy agency snooping on us. We've caught and rebuked foreign spy agencies all the time. The usual punishment is covert retaliation (escalating malware attacks, etc.), and the times when it isn't covert (like with the Russia revelations), responses usually involve sanctions and condemnation.
NSA would be doing the American people a disservice if they weren't competing with the rest of the spy agencies out there. It's just a fact of life. We just want them to do it without warrantless mass surveillance of US citizens.
>It was proven that the CIA had knowledge about the attack before it happened...
They didn't. To suggest they did is to allege a massive conspiracy. They received hints it might happen, but intelligence agencies receive tens of thousands to millions of pieces of new information per week, 99.99% of which turns out to be nothing. You can apply this argument to almost every war or attack in history (including Pearl Harbor). Sieving the signal out of the noise isn't easy.
I'm an American but neither a nationalist nor a patriot. I just realize they're doing their job. I also realize and acknowledge Russia wouldn't be doing its job properly if they didn't try to influence the Presidential election.