First, I don't know what the value of the distinction you are trying to make is.  People are not absolutes in general.  So, even though someone may say profess to be a "conservative", they may in fact vote or favor things that are not in line with a "conservative" position.  For example, despite the label of "conservative", Republicans in both the White House and Congress dramatically increased deficit spending and dramatically expanded Medicare by adding the prescription drug benefit.  These are a few examples, but understandably you can see that a label represents an absolute to which politicians can defy on a regular basis.

Also, I think the distinctions you are trying to make are irrelevant to the terms liberal and progressive.  First, does anyone not support our all volunteer military?  I'll grant that there may be, but they are an extreme minority that has no representation (i.e. elected officials or party leadership) in either political party or even within major groups that call themselves progressive, liberal, moderate or conservative. 

On immigration, Karl Rove and George Bush support a path to citizenship for illegal immigrants.  They were pushing hard for the passage of that comprehensive immigration reform package.  Since they advocate "amnesty", does that make them liberal or progressive?  Also, in my mind, immigration is not a liberal, progressive, or even conservative issue.  It is a simply a divide between idealism and realism.

Finally, I think a problem with your question is the assumption that progressive or liberal encompasses a defined set of founding ideas, principles, and policies.  This may be true for the term conservative where you had Barry Goldwater and Milton Friedman defining a movement.  And so you have organizations today like the Heritage Foundation, CATO, and the American Enterprise Institute (to name a few) that do nothing but define what it is to be conservative. 

I take it MoveOn.org, Answer Coalition, Media Matters are Progressive and Brookings, Rainbow Push, are liberal.

I don't understand what this has to do with anything that I put forward, but regardless I'll take you up on this tangent.

With the exception of the Brookings Institution, none of the organizations you mention are solely purposed with formulating policy.  They may advocate specific positions and specific laws drafted by others, but rarely are they doing the kind of detailed policy formulation, research, and analysis work that say Brookings does. 

Also, the Brookings Institution is not "liberal" under any generally accepted definition of the word.  Just take a look at any of their Op-Ed pieces to verify for yourself.

And last, you make a distinction without defining what "liberal" and "progressive" are.  You challenged the community to answer some questions regarding the distinction between two terms.  And I responded with my opinion: that such labels are meaningless.  Therefore, the distinction is equivalently meaningless.  So, I think in order to forward the discussion it is incumbent upon you to define the terms "liberal" and "progressive" as you see them and state why you think this distinction is meaningful.

at Wikipedia on this subject:

The term "progressive" is today often used in place of "liberal". Although the two are related in some ways, they are separate and distinct political ideologies. According to John Halpin, senior advisor on the staff of the Center for American Progress, "Progressivism is an orientation towards politics, It's not a long-standing ideology like liberalism, but an historically-grounded concept... that accepts the world as dynamic." Progressives see progressivism as an attitude towards the world of politics that is broader than conservatism vs. liberalism, and as an attempt to break free from what they consider to be a false and divisive dichotomy.

Personally, I consider myself a progressive (per the discussion above) rather than a liberal.  However, I have great respect for liberalism, particulary its "concept of natural rights and civil liberties, and the belief that the major purpose of the government is to protect those rights."  Ultimately, though, I see myself as a progressive in the tradition of Teddy Roosevelt.

Beyond the constraints of liberal and conservative...  How is that different from a "moderate"?  Do liberals and conservatives fail to see the world as dynamic?  If progressivism is a movement that seeks to break free from the "false and divisive dichotomy" that is liberalism and conservatism, what is its philosophy that differentiates it?

And on the Teddy Roosevelt tradition, does that extend to foreign policy?