There is no substantial organized political movement with the intention or capabilities to represent a threat to the United States government or way of life. Underneath the glamor of public school textbooks, America has a long history of low level violence, civil disturbances, anti-immigration sentiment, organized crime, and political radicalization; whether it's frontier violence, strike-breakers, anarchists, or the Ku Klux Klan. Howard Zinn's A People's History of the United States is essentially a laundry list of civil disturbances in American history. America has experienced, and survived, much worst, and in many ways, the democratic system emerged stronger afterwards. In my opinion, the long-view concern is how opposition to first the war in Iraq and now "Wall Street" (as a representation of the capital class) will continue to emerge, evolve, organize, and potentially radicalize as Americans are exposed to future challenges to domestic stability; and, in turn, how that elicits a response from the right. It will require another series of shock events, say an apparently sudden war and equally rapid and surprising defeat by another major power like China, that finally drives home the realization of America's decline.

Are these domestic issues national security concerns? (use whatever definition of national security you prefer)
Yes, but only to the extent they hinder America's capacity to preserve its political sovereignty and territorial integrity. So far, all of the issues you listed are minor.

Will these issues eventually be resolved through the democratic process?
What do you mean by 'resolved'? All of these issues have been present in American history in one way or another.

If the economy continues on its current path, will social unrest/civil disturbance increase? Will they turn more violent?
No, insofar that until an organized political movement emerges, these events should be classified as 'minor'. Basically, people still have something to lose, so why risk that on the streets? When the professional middle class takes to the streets in large numbers and begins agitating for political reform, that is when we should be concerned.

Could foreign influence make these domestic issue worse?
Potentially.

What role does citizenship (not the legal process of becoming a citizen) play in National Security?
None.

Should the US reshape its national security investment strategy to better address these issues?
No. Right now, these issues are solidly political issues since they are minor national security concerns.