I think you've missed one of the most important points about representative democracy. A representative's job (and in this case I mean both houses of congress and the president) is to know the most he or she possibly can about each issue he or she is to vote on. This is a more than full-time job. I'm a pretty informed voter, but I couldn't possibly be fully informed about every issue that congress and the president face. They usually aren't either, but in the ideal they are better informed than I am. When you vote, you should be voting for the person who you think will do his or her best to stay informed on the issues (or to work with people who are well informed) and will make the best decisions based on that information. That becomes even more true when we get into issues of national security because much of the information required to make informed decisions is classified.
And to respond to the main question of the discussion, I'm pretty committed to voting for Obama. I think it's past time to set the divisive issues of the baby-boomer generation behind us and try to move forward in a way that includes the most people possible, regardless of whether I agree with them or not. Obama is far more liberal (I lean more libertarian than any other particular label) than I'd normally be comfortable with. But I think he would be the best leader of any of the candidates (including the ones who have dropped out), and maybe equally importantly, I think he has a strong chance of changing the tone of US politics. And that is something I think we desperately need. I'm disgusted by the idea of 4-8 more years of Clintonian-Rovian "win at all costs and never admit a mistake" politics.