To all but the first, "yes." If that idea frightens you more than the greater number of murders or accidents or disasters, that kill more people and do more damage, then you have lost perspective - probably because you have fallen victim to fear mongering.

To the first, it depends on what we have to trade away and on what we get in return. There will always be risks, because our resources are finite and the world is occasionally hostile. A 9/11 scale terrorist attack happening every few years is bad, but unless the resources we shift there make a bigger difference in reducing those threats they can make elsewhere, you should be "content" in the sense that that is the result of the policy that you should prefer. In this context, freedom/power can be viewed as an important resource: power in the hands of the security apparatus makes them more effective, but freedom in the hands of the people helps to protect against government abuses (in the extreme, tyranny - but things don't have to get there for it to be important).