It was excellent, I really want the second season to be released as soon as possible so I can see what happens next. No spoilers except to say that you don't have to worry about the rest of the season veering off track, the last few episodes are the best ones.
I agree with most of your review, but I was not as bothered by the portrayal of the union battle as you were. While the show certainly showed the Democrats stabbing the unions in the back, I think what the show was trying to show was that the politicians will turn their backs on their own constituents if doing so gives them more power. When he brings out the food to the workers and they gobble it up it is showing how the Democrats put on a nice face for the unions, but don't always have their interests in mind.
The show was made by liberals but they chose a Democrat as the lead villain because I think they wanted to show that the working people have no one to stand up for them, if they would have chose a Republican as the villain then they would have had to portray the Democrats standing up to that villain. By focusing on a corrupt Blue Dog Democrat they give the show a darker outlook because the people are put in a position with no hope of representation, if they vote out Underwood they will be stuck with a Republican who acts just like Underwood. It is a very cynical show that suggests that damn near everyone in Washington is more concerned about their own personal gain than they are concerned about the people they are supposed to serve. It may be cynical, but I think there is a lot of truth to that outlook, there are many elections in which people are asked to choose between a Blue Dog and a Republican and the sort of union busting portrayed in the show is what happens when people are not given a real choice.