Whether or not the data is analyzed in a timely manner is irrelevant to its' legality or morality (speaking solely on spying within the US.) One would assume that both competent terrorists and Russia have had proper NSA counter measures in place far before Snowden's leak. Indeed, bin Laden was able to remain hidden for a very long time. What we have seen is plenty of stories of dumb Westerners attempting to become jihadists.
NSA blackmail is far fetched. Of immediate concern is NSA employees inappropriately spying on other Americans. This has already happened multiple times that we know about: http://www.bloomberg.com/news/2013-08-23/nsa-analysts-intent... Lapses at the companies which conduct bulk top secret clearance checks should only raise more alarms.
The most recent doc leak demonstrates that not only was a contractor such as Snowden capable of searching and extracting data but it was done so without the NSA having any idea. No paper trail. How did someone get certain information on you or did they? No one knows. Blackmail hardly necessary if politically charged attacks reap large rewards by crippling a citizen running for office or an attorney general investigating a corrupt corporation. Anyone could be targeted: a sitting congressman, someone running for office, a federal judge, friends, children, family. Conducted in a veil of secrecy with secret oversight guarded by a national security mandate leaves no accountability: a total abandonment of America's foundation of checks and balances.
In the longer term, this behavior is more grim than that posed by a rogue individual such as Snowden. If the existence of the NSA and its spying on Americans is fundamental to national security anyone who opposes this behavior is as big of a threat as a bin Laden. It becomes appropriate to target not only Americans but also sitting government officials who pose a threat. Congress's muted reactions could leave one to believe this is already the reality. At the least, the fear is there.
Integrity and values are shallow and attach only individually to a mortal man. If an institution or government is built without transparency and without a balance of power, eventually, at some time bad people will gain control. They may be intentionally bad, seeking nefarious and self-motivated gain, or it may be unintentional: simply an absence of knowledge in a certain area which produces disastrous decision making. The Catholic church abuse scandals presented a mixture of both. Because the institution was deeply opaque and without proper checks and balances, widespread failure occurred. Even lives devoted to continuous moral contemplations, recitations and displays of charity could make up for this.