Sorry to sound harsh, but (a) did you read my question in full, and (b) is this a cut and paste answer? Because it's not really very helpful.
I said that my site lost 80% of its traffic over the weekend of 27-29 September 2012. This means it's either Panda or EMD. It's not EMD (or if it is, it's a pretty unfair EMD penalty on a site with around 100 quality posts.
I said that I received no warnings or notices from Google and that I have checked every single post and page on the site for duplicate content using Copyscape. I also said Google has confirmed no manual penalty.
There is no list of Panda triggers "above", unless you are referring to my own checklist of the things I've already looked at.
Almost all my posts are long and detailed (many over 1000 words). The shortest post on my site would be 150 words. I run minimal advertising, and no more than one ad on any page or post. I don't have subscribe forms or internal banners.
I get that you appear to be from an SEO company and I appreciate you are trying to help me, really I do. And I thank you for taking the time. But I have heard all this before, over and over, on other forums. I am posting here because I desperately need expert help. I have been working on recovery for two months now and have done everything anyone has ever suggested to try to recover my site. I'm near the end of the process (I hope), not at the beginning.