Wow, just happened to see this post. I've always been interested in North Korea, but as western I'm quite afraid something could go wrong and I could get arrested. Of course, in most cases a western tourist has been arrested it has been for clear reasons - like trying to steal something from the country.
However, are you worried you might get in trouble with the authorities as you are taking pictures and writing a blog about their country?
Get out of there as soon as you can i agree
Americans are at much greater risk than e.g. Europeans given the potential for negotiational leverage. There have been very, very few Europeans that have come into trouble in history. As long as you listen to the guidelines given within the country, you are perfectly fine.
As for the picture sharing: I am well aware I can not share everything in here, and I will not. However, I will do my best to show you as much as possible without jeopardizing others (i.e. my guides could get into trouble in case I share some of my pictures online).