I haven't been able to satisfy any clear conditions for being good or bad guys. Not even for being patriots or not.

Ultimately it doesn't matter. Their jobs are inherently evil. Spying always has been, but this is different because it involves everyone (even without being suspect) and costs for additional invasion of privacy\surveillance is negligible. Meaning a single person that doesn't do his/her job can ruin the world (in many scenario's). Looking at Snowden there is not the kind of security procedures to prevent it, either.

So. Are the NSA guys good guys? Well. They're the enemy of the people, as they invade their privacy and therewith their safety. If you can be blackmailed, studied, influenced, etc. you are weak and vulnerable. Preaching to the choir, I guess. So I cannot call them good guys by a very long shot.

Are the NSA guys bad guys? Well, they do anything to protect their nation from whatever attack could happen (bad for non-US; me). They steal secrets for their government (bad for non-US; me). They assist foreign secret agencies in subverting or avoiding legal restrictions put in place to protect citizens as (real/wise/elected) politicians see fit. (very bad for non-US; me) 

Uh. Yeah. I guess they're the bad guys. I usually feel like they are soldiers on a certain mission, and so no blame comes to them. But I feel more strongly that the organization is build to produce law-breaking, privacy-destroying, unethical, unfriendly, aggressive, anticompetative, distracting and confusing and ultimately just mean practices.

So yes: the NSA is EVIL to the maximum realistic extend. 

The NSA's people enjoy a margin of appreciation. They're doing a job. They have their reasons. But I do believe most of them are keenly aware of the extremely large quantity of thoroughly unethical things their organization is doing, and must be considered at least partially responsible.